Treasury Stock or Treasury Shares Are Shares a Firm Has

Treasury stock or treasury shares are shares a firm has previously issued and later reacquired. Which of the following is/are true?

A) To fulfill commitments to deliver shares to its employees under employee stock option plans, the employer can reacquire shares so that the number of shares outstanding remains approximately constant.
B) Doing so avoids diluting existing shareholders' voting interest and perhaps maintaining earnings per share.
C) The firm would project the expected number of shares needed for the exercise of employee stock options and repurchase that amount of shares in the open market.
D) all of the above
E) none of the above