The smaller a population of organisms of a particular species, the A.
more likely one of the organisms is to adapt to a changing environment
B.
more likely a mutation is to arise
C.
less likely the species will be able to survive in a changing environment
D.
less likely natural selection is to affect the population

The correct answer is - D. less likely natural selection is to affect the population

Explanation:

The larger population of a species tends to produce more mutant individuals per generation than a smaller population per generation. In a larger population, it assists to get more genotypes and gets optimal genotypes quicker than smaller populations.

In larger populations, the process of natural selection is more effective and for the smaller population   Second, natural selection is less likely to affect the population which leads to less genetic diversity or change in order to survive due to stochastic sampling error  as some allele loss in random selection.