He could race multiple cars with different weight added on them and do multiple races (just to be sure) and see if his theory was correct, if not he should right down what he has learned from his experience! :D
-You'll never learn if u don't try ;)
Answer:
I would say B
Explanation:
Because atural selection is the mechanism for how evolution occurs over time. Basically, natural selection says that individuals within a population of a species that have favorable adaptations for their environment will live long enough to reproduce and pass down those desirable traits to their offspring.