HCL is secreted by the parietal cell of the stomach. The HCL plays many roles in the stomach. HCL creates an acidic environment in the stomach which helps in converting pepsinogen into pepsin which is necessary to start the digestion of protein.
The highly acidic nature of the stomach helps in killing the microbes that came with the food in the body or stomach. So by killing the microbes associated with food it helps in preventing foodborne diseases. Therefore all the option is correct.
