Refer to the Table Below Summarizing Data Obtained from Mutation

Refer to the table below summarizing data obtained from mutation experiments on a protein enzyme. Specific amino acid substitutions were made at residue 107, which is occupied by a serine residue in the normal protein.After the mutant proteins were made and purified, their enzymatic activities were measured and expressed as a percentage of unmutated protein's enzyme activity.Which statement provides the most plausible explanation of why such widely different changes in activity of the enzyme were observed?

A) Some mutations lead to disruption of an important salt bridge in the protein, while others do not.
B) Some mutations insert hydrophilic residues into a hydrophobic region of the protein, while others do not.
C) Some mutations insert very large residues into a region of the protein that can accommodate only small side chains, while others do not.
D) Some mutations remove a hydroxyl group in the side chain of residue 107, while others do not.
E) Some mutations replace a hydroxyl group with a basic group, while others replace a hydroxyl group with an acidic group.