Answer:
c. They may evolve into two separate species as a result of disruptive selection
Step-by-step explanation:
Disruptive selection is a type of natural selection wherein some extreme change in the surroundings favor two distinct phenotypes while trimming off the mean. Here, the environmental conditions favor more than one phenotype. In the given example, disruptive selection would favor the light-colored lizards in the sandy region while the dark-colored would be favored in rocky regions due to their respective survival success.
With time, these two populations would accumulate more variations and reproductive isolation would not allow them to interbreed and thereby two distinct species of lizards would evolve.