Why is pepsin secreted as pepsinogen rather than as active pepsin inside gastric glands?

• A. Pepsinogen is less energy expensive to produce than pepsin and therefore secreted to conserve ATP inside gland cells
• B. Pepsinogen acts as a hormone to stimulate mucus production rather than as an enzyme, and is later repurposed into pepsin by liver enzymes
• C. To prevent autodigestion of the gastric gland proteins and cells; pepsinogen is inactive until converted to pepsin by low pH in the stomach lumen
• D. Pepsinogen functions as an acid buffer inside glands and only becomes enzymatically active when neutral pH is reached, which never happens in the lumen

Answer: (C)