(State or Other Jurisdiction

of Incorporation)

(Commission

File Number)

(I.R.S. Employer

Identification No.)

1800 THREE LINCOLN CENTRE,

5430 LBJ FREEWAY, DALLAS, TEXAS

Title of each class

Trading
Symbol

Name of each exchange

on which registered

Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year.

updates to align with and conform to changes in the Texas Business Organizations Code and the Virginia Stock Corporation Act, including, without limitation, revisions to expressly state that the Board can elect to conduct shareholder meetings by means of remote communication;

amendments to the procedural and disclosure requirements for shareholders intending to nominate directors or propose other business (other than proposals to be included in the Company’s proxy statement pursuant to Rule 14a-8 under the Securities Exchange Act of 1934, as amended (the “Exchange Act”)) at annual or special meetings of shareholders, including, without limitation, to:

revise the advance notice window for shareholders intending to nominate directors or propose other business at an annual meeting of shareholders to not earlier than one hundred twenty days nor later than ninety days prior to the anniversary date of the previous year’s annual meeting;

revise the nomination window for shareholders intending to nominate directors at a special meeting of shareholders to not earlier than one hundred twenty days nor later than ninety days prior to such special meeting or the tenth day following the date the Company announces the date of the special meeting;

require additional background information and disclosures regarding shareholder director nominees;

require additional background information and disclosures regarding shareholders proposing director nominations and other business and other persons related to a shareholder’s solicitation of proxies;

clarify that certain informational requirements applicable to shareholders that are entities also encompass individuals who directly or indirectly control such entities (but not passive investors in such entities);

clarify that the number of nominees that a shareholder may nominate shall not exceed the number of directors to be elected at the meeting;

require any shareholder submitting a nomination notice to make a representation and applicable confirmation as to whether such shareholder intends to solicit proxies in support of director nominees other than the Board’s nominees in accordance with Rule 14a-19 of the Exchange Act (i.e., the “universal proxy card” rules) and to provide evidence that the shareholder has complied with such requirements;

require any shareholder submitting a proposal of other business to make a representation as to whether such shareholder intends to solicit proxies from at least the percentage of the Company’s voting shares required under applicable law to carry the proposal; and

clarify that a failure to provide such disclosure or comply with such requirements will result in a shareholder’s nomination or proposal of other business being disregarded;

amendments to revise the voting standard to a majority of votes cast for matters other than the election of directors and to clarify that directors shall be elected by a majority vote of the shares of common stock entitled to vote in the election of directors and represented in person or by proxy at a meeting of shareholders at which a quorum is present;

amendments to provide that the number of directors of the Company shall be no fewer than seven and no greater than thirteen and that changes to the range of the Board size may be effected through the Bylaws;

requiring that a shareholder directly or indirectly soliciting proxies from other shareholders use a proxy card color other than white; and

deleting outdated references and making technical and conforming revisions and clarifications.

Financial Statements and Exhibits.

Exhibit
Number

Description

/s/ KAREN E. HARTSFIELD

Senior Vice President, General Counsel and

Corporate Secretary