Which component of gastric juice is most
helpful in preventing the stomach from
digesting itself?

Of these 5 components, pepsin is the principal enzyme involved in digestion of protein. However, pepsin is released in its inactive form, or zymogen form, known as pepsinogen. By secreting pepsin in its inactive form, the stomach prevents digestion of protective proteins in the lining of the digestive tract.

Explanation:

i believe it would be the lungs.