Answer:
c. Mutations that alter the genetic makeup of the population must not occur.
Step-by-step explanation:
According to Hardy–Weinberg principle, allele frequencies of a population do not change from generation to generation if:
a) The population size is large.
b) There are no operative evolutionary forces in the population. The evolutionary processes that disturb the Hardy–Weinberg equilibrium are mutation, genetic drift, gene flow and natural selection.
Hence, to keep the allele frequency constant, a population should not exhibit mutations.