Which sentence has correct capitalization?

Question

A.
Buzz Aldrin, an astronaut for Nasa, was the second man in history to walk on the Moon.
B.
Buzz Aldrin, an astronaut for NASA, was the second man in history to walk on the Moon.
C.
Buzz Aldrin, an astronaut for nasa, was the second man in history to walk on the Moon.
D.
Buzz aldrin, an astronaut for NASA, was the second man in history to walk on the Moon.

Answer 1

The sentence with correct capitalization is:

B. Buzz Aldrin, an astronaut for NASA, was the second man in history to walk on the Moon.