In chromatin, substitution mutations are most common in linker regions. Option d is the correct answer.
Mutation by substitution When one nucleotide base is replaced by another, this occurs. Mismatch mutation A type of substitution mutation in which a single nucleotide is replaced, resulting in the coding of an incorrect amino acid, which usually results in a malfunctioning protein. Silent mutations are the result of genetic code redundancy (degeneracy): This is false, as silent mutations are the result of a base substitution that has no discernible effect on a protein's amino acid sequence.