What Molecular Mechanism/feature Does Site-Directed Mutagenesis Exploit to Introduce a Mutation

Multiple Choice

What molecular mechanism/feature does site-directed mutagenesis exploit to introduce a mutation at a specific site?

A) flanking complementary bound nucleotides permit non-complementary base pairing
B) methylated nucleotides disrupt DNA polymeraseʹs proofreading
C) nucleotide substitution when one is depleted
D) transposase-induced base pair changes