Suggest why the ph of the gut secretions varies at different regions in gut answer key anatomy

The answer in this question is just easy and simple, since there are lots of different enzymes being secreted in the stomach (the enzymes are made of protein and can be denatured by alternation of pH, each of these enzymes required to have a specific optimal pH. 

The correct answer is because they work at different pH levels.

Explanation:

The pH varies because the different enzymes secreted in the stomach work at different pH levels. Gastric secretion is the most important stage of digestion since when the food comes into contact with a low pH and the enzymes present, they dissociate it and denature the proteins present.

Have a nice day!

Ithink the answer is a or d.