Final answer:
During an infection, the aggregation of viral particles is observed, which is not a result of antibody-antigen interactions.
Step-by-step explanation:
During an infection, a. B cell proliferation, c. systemic temperature increase, and d. antibody secretion are all observed as a result of antibody-antigen interactions. However, b. aggregation of viral particles is not a result of antibody-antigen interactions. Aggregation of viral particles occurs when viruses cluster together, making it easier for the immune system to destroy them. This process is not dependent on the presence of antibodies.