The correct answer is B. Lymphocytes.
Lymphocytes are a type of white blood cell that play a major role in the immune system. They are responsible for producing antibodies, which are proteins that help the body fight off infection.
Monocytes are another type of white blood cell, but they do not produce antibodies. They are phagocytes, which means they engulf and destroy bacteria and other foreign invaders.
Eosinophils and neutrophils are also white blood cells, but they are not involved in the production of antibodies. Eosinophils are involved in allergic reactions, while neutrophils are involved in fighting infections.
In conclusion, the correct answer is B. Lymphocytes. Lymphocytes are the only type of white blood cell that produces antibodies.