They can all make you ill and be dangerous for the body
Esophagus
Stomach
Small intestine
Large intestine
Cloaca
That's just the alimentary track (minus the couple that come before esophagus such as mouth and pharynx) so if you need digestive glands and accessory organs let me know cause I know those too
The answer is A.
You can remember this by thinking that since there was no change in the amino acid sequence, the mutation is silent in the fact that it didn't cause any trouble in the amino acid sequence.
