Based upon fossil records, the first life first formed on the earth at least

If you can provide evidence/ explanation for these two that'd be great because I rather learn about this for my AP exam than just pass the course blindly.

Based upon fossil records, the first life first formed on the earth at least
Answer
      a. 3.5 million years ago.
      b. about four thousand years ago.
      c. 3.5 billion years ago.
      d. 265 million years ago.
      e. 2.2 billion years ago.

Illustrated by the way a flower discriminates between pollen on the same species and pollen of different species.

I. Temporal Isolation
II. Habitat Isolation
III. Gametic Isolation
IV. Hybrid Sterility
V. Hybrid Inviability