"Water in the form of vapor" is the choice among the choices given in the question that shows the form in which water enters the atmosphere. The correct option among all the options that are given in the question is the second option or option "B". I hope the answer has helped you.
Characters, A backround story
I find that the best answer is the following one:
c. determined by factors outside our control
For example, even though life is very hard in the very hot and the very cold regions, we can't control it: so this is an example of a physical environment that is hard to control.
In comparison, it is often easier to describe than our social environment.
