[Solved] The human body uses three lines of defense to protect against pathogens. Match each of the following categories of defense to the type of cell or mechanism involved in the defense. Answers may be used more than once. -cytotoxic T cells A)physical or chemical barrier B)specific defense mechanism C)nonspecific defense mechanism Paternity Uncertainty: The impossibility for a male to be absolutely certain that he is the biological father of a child, due to the nature of internal fertilization and gestation in females. Extradyadic Sex: Sexual activity that occurs outside of a committed relationship, often considered a breach of exclusivity. Erotic Plasticity: The degree to which an individual's sex drive and sexual interests can change based on various social, environmental, and situational factors. Cheating: The act of being dishonest, deceitful, or breaking rules to gain an unfair advantage.