Q: You are presented with the quiz "Where do thunderstorms come from?" But you don't know the answer, so you turn to your teacher to ask for hints. He says that "cold fronts cause thunderstorms as they pass by" and "if cold air is advancing on warm air, the front is called a cold front". So, what's the best answer to the question?

Select from the following. a. Too much rain in the clouds. b. When the environment is too cold. c. Earth's axis of rotation is tilted. d. fissures of hot, acidic water. e. More than one trophic level.. f. it flows to a lower level. g. Dryness in the environment. h. When cold air advances on warm air.
A:
h.