The process most likely led to the change in the lizard population is the natural selection acting on a dominant trait. So, the correct option is C.
What do you mean by Natural selection?
Natural selection is a selection made by nature on the basis of the most favorable variations among all the variations.
The proportion of Z-allele increases from year 1 to year 50. So, this allele generally contains a dominant trait, because dominant traits are visible in organisms when they are present. While recessive traits are not identified or visible even they are present in organisms.
Therefore, the process most likely led to the change in the lizard population is the natural selection acting on a dominant trait.
To learn more about traits and their influence, refer to the link:
https://brainly.com/question/4619327