Interstellar Clouds Are

Multiple Choice

Interstellar clouds are

A) hydrogen gas,condensed out of the interstellar medium,like water clouds in the Earth's atmosphere.
B) regions where hydrogen tends to be denser than the surrounding gas.
C) regions where water condenses out of the interstellar medium.
D) oxygen gas,condensed out of the interstellar medium,like water clouds in the Earth's atmosphere.