Autobiographical memories
The brain is part of the central nervous system
Natural selection results in (e) advantageous traits becoming more common in a population.
<h2><u>Answer:</u></h2>
The correct option is B (The longer-spined sea urchins existed before the shorter-spined sea urchins.)
<h3><u>Explanation:</u></h3>
The more drawn out spined ocean urchins existed before the shorter-spined ocean urchins.
Since the shorter spined urchins are higher up, that demonstrates that they developed from the more drawn out spined urchins, implying that having the shorter spines was useful to them as an animal types, so the shorter spines came AFTER the more extended spines.