Natural selection is the process by which favorable traits tend to increase in frequency over time. how does this experiment illustrate natural selection?

Favorable traits that increase in frequency over time is a product of natural selection. Natural selection allows the natural flow of evolution where the traits that are more convenient for the specie to have in order to survive is frequently manifested throughout the generations. While on the other hand, the trait that is inconvenient and is useless is diminished.

The answer is the first one A) cementation