Which of the following is not a method of expelling pathogens from the body?

The option identifying "digesting" as not a method of expelling pathogens from the body is correct because digestion primarily involves the breakdown and assimilation of nutrients from food, rather than the removal of pathogens. While the digestive system does play a role in the immune response by breaking down harmful microbes ingested through food, it does not actively expel them from the body in the same way that the other options do.

Coughing and sneezing are reflexive actions aimed at clearing irritants and pathogens from the respiratory passages. These actions serve as protective mechanisms, rapidly expelling airborne particles and microorganisms. Similarly, vomiting serves as a mechanism for expelling harmful substances and pathogens from the stomach and upper digestive tract, protecting the body from potential toxins or infections.

In contrast, digestion’s primary function is nutrient absorption rather than pathogen expulsion, making it the accurate choice in this context.