Question

which statement accurately describes the atmospheres of the inner planets?
mars has no atmosphere.
mercury has a thick atmosphere.
the atmospheres of mars and venus are similar in composition.
the atmospheres of earth and venus are similar in composition.

Explanation:

Both Mars and Venus have atmospheres mainly composed of carbon - dioxide. Mars has a thin atmosphere while Venus has a thick one. Mars does have an atmosphere, so option A is incorrect. Mercury has a very thin exosphere, not a thick atmosphere, so option B is incorrect. Earth's atmosphere is mainly nitrogen and oxygen while Venus's is mainly carbon - dioxide, so option D is incorrect.

Answer:

C. The atmospheres of Mars and Venus are similar in composition.