Final answer:
The humoral immune response is attributed to B lymphocytes (B-cells), which produce antibodies that circulate in body fluids to target pathogens. Therefore, the correct answer to the question is (C) B lymphocytes.
Step-by-step explanation:
The humoral immune response is attributed to the action of B lymphocytes (B-cells). These cells are responsible for producing antibodies that circulate in the body's fluids, or humors, particularly the blood plasma and lymph, hence the term 'humoral' immunity. When B cells come into contact with an antigen, they can differentiate into plasma cells that secrete antibodies specific to that antigen.
This contrasts with the cell-mediated immune response, which involves T lymphocytes and does not directly produce antibodies but rather activates other immune cells and directs the immune response. Therefore, the correct answer to the question is (C) B lymphocytes.