The Stomach Can Be Considered a First Line of Defense

The stomach can be considered a first line of defense against microbial infections because:

A) most microorganisms are susceptible to the antibiotics and alkaline pH present in the stomach.
B) most microorganisms are killed by the liver enzymes that are emptied into the stomach during a meal.
C) the stomach produces proteases, which attacks the lipopolysaccharide cell wall of the organisms.
D) most microorganisms are susceptible to the acid pH of the stomach.