Question

what cells produce antibodies? helper t lymphocytes killer t lymphocytes phagocytes plasma cells

Explanation:

Plasma cells are specialized immune - cells that secrete antibodies. Helper T lymphocytes assist in the activation of B - cells which can differentiate into plasma cells, but they don't produce antibodies directly. Killer T lymphocytes target and kill infected or abnormal cells. Phagocytes engulf and digest pathogens.

Answer:

Plasma cells