Which of the Following Events Does Not Automatically Terminate an S

Which of the following events does not automatically terminate an S corporation election?

A) One of the corporation's 100 shareholders transfers his shares to three unrelated friends.
B) The corporation issues a nonvoting preferred class of stock that entitles the holder to receive a greater amount on liquidation.
C) 51 percent of the shareholders consent to file a revocation.
D) One of the corporation's 100 shareholders marries and transfers half of her shares to her husband.