Question

how do scientific theories contribute to the understanding of earth science?
a by providing explanations based on evidence and observations
b by relying solely on personal beliefs about the earths systems
c by stating unproven guesses about earths processes

Explanation:

Scientific theories in Earth - science are based on evidence and observations. They are not formed from personal beliefs or unproven guesses. Evidence - based explanations help in understanding Earth's systems and processes.

Answer:

A. by providing explanations based on evidence and observations