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.