Question Detail
Question
According to evolutionary history, approximately how long have animal forms been undergoing adaptation and diversification?
Correct Answer
Option A is the correct answer.
Detailed Explanation
The source states that evolutionary history spans over 600 million years, leading to the current variety of body plans. A distractor like 1.4 billion might be confused with the number of described species.
Hint
Consider the timeframe mentioned in the introduction regarding the timeline of animal evolution.