What is the primary action of bactericidal agents?

The primary action of bactericidal agents is to kill bacteria directly. These agents work by targeting essential cellular structures or functions in bacteria, leading to cell death. This can be achieved through various mechanisms, such as damaging the bacterial cell wall, interfering with protein synthesis, or disrupting metabolic processes critical for bacterial survival. By effectively eliminating bacteria, bactericidal agents are crucial in treating bacterial infections and ensuring that harmful pathogens do not proliferate within a host.

Other options involve different actions: while some agents may hinder the growth of fungi or inhibit viral replication, those are not the focus of bactericidal agents which are specifically designed for bacterial elimination. Disrupting cell membranes is a mechanism that can be a part of how some bactericidal agents work, but it is not the primary action overall associated with all bactericidal agents. The fundamental role remains the direct killing of bacteria, which solidifies option B as the correct choice.