Who's one the biggest challenges in designing a spacesuit for Mars?

Who's one the biggest challenges in designing a spacesuit for Mars?
A.It has be heavy to prevent astronauts from floating away.
B.It must also work as a SCUBA device.
C.It needs to double as a hovercraft.
D.It must be lightweight and easy to mover in.
正确答案：It must be lightweight and easy to mover in.