I think the correct answer is D
The answer is, "B", "Ribosomal RNA".
Random changes in allele frequency in a population are usually called genetic drift. The reason why this is the answer is because it is a very specific word which is used to describe exactly that - random changes in allele frequency.
All the other cases; answers, here aren't correct and don't apply.
230 is your anwser! sorry bad english
