The immune system has 3 main types of white blood cells called T cells, B cells, and A) pathogens
B) antibodies
C) macrophages
D) antigens

Explanation:

A lymphocyte is a type of white blood cell in the immune system of jawed vertebrates.[1] Lymphocytes include natural killer cells (which function in cell-mediated, cytotoxic innate immunity), T cells (for cell-mediated, cytotoxic adaptive immunity), and B cells (for humoral, antibody-driven adaptive immunity).[2][3] They are the main type of cell found in lymph, which prompted the name "lymphocyte".[4]Lymphocyte

A scanning electron microscope (SEM) image of a single human lymphocyte

DetailsSystemImmune systemFunctionWhite blood cellIdentifiersMeSHD008214THH2.00.04.1.02002FMA84065 62863, 84065Anatomical terms of microanatomy

[edit on Wikidata]

Lymphocytes make up between 18% and 42% of circulating leukocytes.[2]

you know they are heterozygous for a trait because they have it as jj or jj.