A patient with a B-cell deficiency will most likely exhibit which of the following?

A patient with a B-cell deficiency is most likely to exhibit increased bacterial infections, which is why this answer is the most appropriate. B-cells play a crucial role in the adaptive immune response, particularly in the production of antibodies. These antibodies are essential for neutralizing pathogens such as bacteria and facilitating their removal from the body. When B-cells are deficient or unable to produce effective antibodies, the patient is left more vulnerable to encapsulated bacteria, which rely heavily on antibody-mediated opsonization for clearance.

In contrast, the susceptibility to viral infections primarily involves the T-cell response, which is not directly affected by B-cell deficiency. Similarly, fungal infections, while they can occur, are more related to T-cell function and innate immunity rather than the presence or absence of B-cells. A normal immune response would imply that all components of the immune system are functioning effectively, which is not the case with a B-cell deficiency. Thus, the presence of increased bacterial infections is a direct consequence of the compromised ability of the immune system to produce antibodies and respond to certain extracellular pathogens.