Answer:
Let's complete the question by writing the sequence, from earliest to most recent options
a. 2 → 1 → 3 → 4
b. 2 → 4 → 3 → 1
c. 2 → 3 → 1 → 4
d. 2 → 1 → 4 → 3
e. 2 → 4 → 1 → 3
It's surely going to be e.
e. 2 → 4 → 1 → 3
2. Cambrian explosion occurs.
4. Vertebrates become top predators in the seas.
1. Protostomes invade terrestrial environments.
3. Deuterostomes invade terrestrial environments.
Got it!