A. Because walking on Mars will be easier than walking on the Moon.B. Because there is mo

A. Because walking on Mars will be easier than walking on the Moon.

B. Because there is more gravity on the Moon than on Mars.

C. Because walking quickly will be more difficult on Mars than on the Moon.

D. Because astronauts on Mars will require more oxygen than on the Moon.

请帮忙给出正确答案和分析，谢谢！