Which blood count is typically elevated in a patient with mononucleosis?

The elevation of lymphocytes and monocytes in a patient with mononucleosis is a key feature of this condition, which is primarily caused by the Epstein-Barr virus (EBV). In viral infections like mononucleosis, the immune response often involves an increase in lymphocytes, particularly atypical lymphocytes, as the body attempts to fight off the virus. Monocytes may also be elevated as they play a role in the immune response.

The changes in granulocytes, particularly their decrease, can occur in viral infections since these white blood cells are more responsive to bacterial infections rather than viral ones. Therefore, the correct answer reflects the typical hematological findings associated with mononucleosis, highlighting the response of the immune system to the viral invasion. The other options do not accurately represent the expected changes in blood counts during a mononucleosis infection.