If Vice President Pence Were to Resign from Office

If Vice President Pence were to resign from office

A) President Trump could select any replacement he desired and that person would immediately take office.
B) a new, national election would be held in which both the Democratic and Republican parties could select a single candidate to run.
C) the Senate would select a replacement.
D) President Trump could nominate a replacement, but that replacement would have to be confirmed by a majority vote of both houses of Congress before taking office.