Final answer:
Proteins would be the most affected in digestion if a medication inhibiting the production of HCl in the stomach is taken.
Step-by-step explanation:
The digestion of proteins would be affected the most if a person took a medication that inhibits the production of HCl in the stomach.
The hydrochloric acid (HCl) in gastric juice helps denature food proteins and is necessary for the activation of the enzyme pepsin, which catalyzes the hydrolysis of peptide linkages within protein molecules.
Therefore, if HCl production is inhibited, the process of protein digestion in the stomach would be significantly impacted.