The release of water vapor into the atmosphere generally happens through a combination of two processes: evaporation and

TRANSPIRATION

Explanation:

The plants and trees, after absorbing the water from the roots, are distributed to its entire body, converting it into water vapor, and eliminating the excess amount of water through its leaves, flowers as well as stems. This process of removal of water vapor into the atmosphere is known as transpiration.

Thus, the water vapor is transported into the atmosphere by the combination of both evaporation and transpiration.

Both these processes are a part of the water cycle, which regulates the water from one sphere to another.

d.) greenhouse gases