If the Office of Vice President Becomes Vacant, Which of the Following

If the office of vice president becomes vacant, which of the following is true?

A) It remains unfilled until the next election, and the Speaker of the House becomes president if the president dies.
B) The president nominates a replacement who must be approved by both houses of Congress.
C) The president names a replacement who is not subject to congressional approval.
D) The president names a replacement who must be approved by the Senate.
E) The secretary of state becomes vice president.