Final answer:
Astronauts needed special space suits on the moon to protect against its harsh environment, including extreme temperatures, lack of air, and radiation, ensuring their safety while they performed tasks like collecting moon rocks.
Step-by-step explanation:
Astronauts who landed on the moon needed to wear special space suits primarily B) to protect against extreme temperatures and lack of air. The moon's environment doesn't have a breathable atmosphere, and temperatures can swing dramatically. Space suits provide life support and climate control to keep astronauts alive and well under such extreme conditions. They also guard against solar radiation, micrometeorites, and help in communication. Gathering moon rocks, while one of the tasks astronauts performed, wasn't the primary reason for the suits; it was a benefit of being protected in the suit. And while space suits do look quite cool, the function is far more important than fashion or the fanciful idea of impressing aliens or flying like superheroes.