Answer the following question: You are presented with the question "when is timing critical?" and the following answer choices: - for gravity - Warm air moving into cold air - earth's orbit - when sperm and egg fuse - flow of electrons - earth's rotation - Earth revolving around the sun - movement of tectonic plates Now knowing that fertilization occurs when a sperm and an egg fuse and fertilization As far as fertilization, timing is critical, choose the best answer.
Answer:
when sperm and egg fuse