Final answer:
In the context of adaptive immunity, B lymphocytes (B cells) bear the primary responsibility for preventing the spread of viruses as they produce antibodies. While macrophages and neutrophils (PMNs) are phagocytic and play significant roles in innate immunity, B cells are pivotal in adaptive immunity.
Step-by-step explanation:
Phagocytes and Adaptive Immunity
The burden of adaptive immunity in preventing the spread of viruses primarily rests on B lymphocytes and T lymphocytes. Macrophages and neutrophils play crucial roles during the innate immune response, providing immediate defense against infections by carrying out phagocytosis. B lymphocytes, also known as B cells, are pivotal in the adaptive immune system because of their role in producing antibodies. These antibodies can neutralize pathogens and mark them for destruction. On the other side, T lymphocytes, or T cells, directly attack infected cells or help orchestrate the immune response.
Macrophages are phagocytes that can both ingest pathogens and promote inflammation by producing chemicals. They are known for their ability to phagocytize pathogens through the formation of a phagosome, which then fuses with lysosomes to destroy the ingested pathogen. This process is an important part of the innate immune response. Neutrophils, or polymorphonuclear cells (PMNs), also have phagocytic capabilities and are involved in the innate immune response as well.
However, when it comes to adaptive immunity and specifically the prevention of viral spread, B Lymphocytes are the primary cells responsible. They produce antibodies that can neutralize viruses and mark them for destruction by other immune cells. Thus, for the given question, the correct answer is B. B Lymphocytes.