Pilots flew on two-person Gemini missions and Apollo flights to the moon these were the last Air Force officers to serve as pilots.

Which correctly shows where a semicolon is needed in the sentence?

A.
Pilots flew on two-person Gemini missions and Apollo flights to the moon these were; the last Air Force officers to serve as pilots.

B.
Pilots flew on two-person Gemini missions and Apollo flights to the moon; these were the last Air Force officers to serve as pilots.

C.
Pilots flew; on two-person Gemini missions and Apollo flights to the moon these were the last Air Force officers to serve as pilots.

D.
Pilots flew on two-person Gemini missions; and Apollo flights to the moon these were the last Air Force officers to serve as pilots.