Two Close Binary Stars Exchange Mass

Multiple Choice

Two close binary stars exchange mass. Which of these does NOT describe a possible outcome of such a mass exchange?

A) The star that was originally smaller can become the larger of the two.
B) An accretion disk can be formed around one of the stars, which can almost block it from view.
C) One of the stars can begin to spin so rapidly that its shape will be distorted.
D) The two stars can merge to form a single star and then fly apart to form two wholly new stars.