What are the major effects of genetic drift on genetic variation within populations

Genetic drift can result in the loss of rare alleles, and can decrease the size of the gene pool. Genetic drift can also cause a new population to be genetically distinct from its original population, which has led to the hypothesis that genetic drift plays a role in the evolution of new species.

it is either c or d and i know for sure it is not a or b

during the process of dna replication, brdu can replace thymidine and incorporate into the newly synthesized dna, cell proliferation thus can be reflected in the extent of brdu incorporation.