What are the three large groups of anti-infective agents?

The correct answer identifies the three large groups of anti-infective agents as antibiotics, antiviral agents, and antifungal agents. Each of these categories plays a crucial role in combating different types of infections caused by bacteria, viruses, and fungi, respectively.

Antibiotics are substances that inhibit the growth of or destroy bacteria. They are used to treat various bacterial infections and come in many forms, including penicillin and cephalosporins. Antiviral agents specifically target viruses, working by preventing their replication or inhibiting their ability to infect host cells. Examples include medications used to treat influenza and HIV. Antifungal agents are used to treat infections caused by fungi, such as those that lead to conditions like athlete's foot or candidiasis.

The other options listed do not accurately represent the main classifications of anti-infective agents. For instance, including laxatives or analgesics in those categories conflates different therapeutic areas that are not focused on treating infections. Therefore, the grouping of antibiotics, antivirals, and antifungals is foundational in pharmacology and critical for effective treatment of infectious diseases.