Which viral infection is associated with the proliferation of B lymphocytes and production of heterophile antibodies?

Infectious Mononucleosis is indeed the correct answer because it is primarily caused by the Epstein-Barr virus (EBV), which targets B lymphocytes. The proliferation of these B cells is a hallmark of the infection and leads to characteristic symptoms such as fatigue, fever, and swollen lymph nodes.

During this immune response, the body produces heterophile antibodies, which are a specific type of antibody that can be detected through serological tests and are indicative of infectious mononucleosis. This is a distinctive feature of the disease, setting it apart from other conditions listed in the options.

The other conditions mentioned do not primarily involve the proliferation of B lymphocytes or the production of heterophile antibodies. Agranulocytosis refers to a severe reduction in the number of neutrophils in the blood, which can lead to increased susceptibility to infections but does not relate to B cell activation. Acute Lymphocytic Leukemia, while involving lymphocytes, is a malignant condition that doesn't focus on the production of heterophile antibodies like mononucleosis does. Neutrophilia indicates a high neutrophil count and is typically a response to bacterial infections or inflammatory conditions, not viral infections linked with B lymphocyte activity.