Read the excerpt below.

One of the West Computers was Katherine Johnson, a central contributor to the first manned flights to space. Her calculations sent the first astronaut, Alan B. Shepard, Jr. into orbit. Due to her success, Johnson worked on many subsequent missions. She was so trusted by the team of astronauts that John Glenn requested she map his flight to space. Katherine Johnson also computed the launch and flight of Apollo 11, which resulted in the first men stepping foot on the moon.

Which of the following statements best summarizes the central idea of the excerpt?

A. Even with hard work, it took the space program nearly eight years to send men to the moon.
John Glenn credited Johnson with helping him become the first man to orbit the moon.
B. Johnson had a long successful career with the space program before retiring in 1986.
C. Johnson was a significant contributor to a number of missions, from a man in space to men on the moon.