How do mutations affect reading frames and potential protein function?

How do mutations affect reading frames and potential protein function?

• A. Indels in multiples of three shift reading frames; point mutations cannot affect amino acids.
• B. Reading frames are unaffected by insertions or deletions.
• C. Indels not in multiples of three shift the reading frame, altering downstream amino acids and often creating premature stop codons; point mutations can be silent, missense, or nonsense.
• D. All mutations always inactivate proteins.

Answer: (C)