Which of the following is an indicator of lymphocytosis?

Lymphocytosis is defined as an increase in lymphocytes, which are a type of white blood cell that plays a crucial role in the immune response. The presence of increased lymphocytes in a blood sample is a key indicator of this condition and can suggest various underlying health issues, such as viral infections, certain chronic inflammatory conditions, or lymphoproliferative disorders.

The other options represent different types of white blood cells and their increases would indicate different conditions. Increased neutrophils typically point to bacterial infections or stress responses, while increased eosinophils are often associated with allergic reactions or parasitic infections. Increased basophils can indicate hypersensitivity reactions or certain blood disorders. Hence, increased lymphocytes is the direct and specific indicator of lymphocytosis.