What is the effect of an anticomplementary substance?

An anticomplementary substance inhibits the action of the immunological complement system. The complement system is a series of proteins that play a crucial role in the immune response by assisting in opsonization of pathogens, promoting inflammation, and directly lysing pathogens. Anticomplementary substances can interfere with specific components of this system, thereby preventing it from functioning effectively. This inhibition can be critical in certain pathological conditions, as well as in laboratory settings where researchers seek to control or study the immune response.

The other options relate to different aspects of immune function. Enhancing complement action refers to processes that would boost the effectiveness of the complement system, which is contrary to the role of an anticomplementary substance. Stimulating antibody production is associated with various immunomodulatory agents, while the activation of T cells is typically influenced by different cytokines and antigen-presenting mechanisms, not by substances that inhibit complement activity. Thus, the correct understanding of an anticomplementary substance lies in its role as an inhibitor of the complement system, aligning with option B.