Each gene pool includes various alleles of genes. The variation occurs both within and among populations, supported by individual carriers of the variant genes. Genetic variation is brought about, fundamentally, by mutation, which is a permanent change in the chemical structure of chromosomes.
Full employment and economic growth are positive effects, so they would not be "a cost of economic instability" - we can reject this option.
The best answer is inflation- it's an economic cost and it has negative effects, such as increasing the prize of the goods faster than wages.
Environmental influences can be separated into shared and non-shared.
The third one because if you look up the question it say what they are in different wording, so I looked at all what they meant so it should be the third one