The low pH of stomach is largely due to

• The low pH of the stomach is largely due to hydrochloric acid (HCl). It is secreted by the parietal cells.
• Hydrochloric acid makes the pH of the stomach acidic or low for the activation of the pepsin enzyme and to kill the harmful bacteria that come with the food.
• Due to the hydrochloric acid in the stomach, the salivary amylase enzyme gets deactivated and no digestion of the starch takes place in the stomach.
• Formic acid is produced by the ant, citric acid is found in the citrus fruit and sulphuric acid is the mineral acid.

Hence, option A is the correct answer.