Compared to Earth's Atmosphere,the Atmosphere of Mars Has Surface Pressures

Compared to Earth's atmosphere,the atmosphere of Mars has surface pressures that are ________.

A) 3 times those on Earth; major gases are water vapor and carbon dioxide
B) 0) 1 times those on Earth; major gases are water vapor and carbon dioxide
C) one-half those on Earth; main gases are methane and nitrogen
D) 1) 5 times those on Earth; main gases are methane and nitrogen