Near the end of both March and September, a. spring begins in both hemispheres.
b. the sun's rays strike Earth with the same intensity everywhere.
Earth's axis is no longer pointing at the North Star.
d. neither end of Earth's axis is tilted toward the sun.
c.

answer: 4

explanation: 8

the principles and empirical processes of discovery and demonstration considered characteristic of or necessary for scientific investigation, generally involving the observation of phenomena, the formulation of a hypothesis concerning the phenomena, experimentation to test the hypothesis, and development of a conclusion that confirms, rejects, or modifies the hypothesis.