write my assignment 112

Which correctly shows where a colon is needed in the sentence? In the early years of the space program: Astronauts studied three complex subjects rocket engines, flight mechanics, and computer theory. B. In the early years of: the space program, astronauts studied three complex subjects rocket engines, flight mechanics, and computer theory. In the early years of the space program, astronauts studied three complex subjects: rocket engines, flight mechanics, and computer theory. In the early years of the space program, astronauts studied: three complex subjects rocket engines, flight mechanics, and computer theory.