Which of the following is a function of antibodies?

Antibodies play a crucial role in the immune system, and one of their primary functions involves the facilitation of the formation of membrane attack complexes. When antibodies bind to antigens on the surface of pathogens such as bacteria, they can activate the complement system, which is a group of proteins that contribute to immune defense. This activation leads to the formation of membrane attack complexes that insert into the pathogen's membrane, creating pores that disrupt the integrity of the cell, ultimately leading to cell lysis and death.

This mechanism is essential in the immune response, as it allows for the effective targeting and elimination of pathogens. The capability of antibodies to initiate such processes reinforces the importance of their role in antibody-mediated immunity.