One of the conditions that must be met for population to be in genetic equilibrium according to Hardy-Weinberg equilibrium is the absence of mutations in a population.
Explanation:
Genetic equilibrium occurs in absence of evolution within the population.
In genetic equilibrium, the gene frequency is stable.
According to Hardy Weinberg equilibrium theory, five conditions must be satisfied:
No mutation in DNA
Large population size
Random mating
No migration
No natural selection
All these conditions are rarely found in real life surroundings. So, according to this theory evolution occurs. Among the five conditions, no mutation and no natural selection are practically not possible.
I would say that answer choice C is the best out of this selection. Carbon is the main element in organic compounds, and organic compounds just so happen to make up the cells that carry out life processes for all living things. Hope this helps.