Which one among the following cells produces antibodies against any foreign antigen?

Lymphocytes, specifically B-lymphocytes (B cells), are the cells responsible for producing antibodies against foreign antigens. When B cells encounter an antigen, they differentiate into plasma cells that secrete antibodies (immunoglobulins) which neutralize the antigen. Erythrocytes (red blood cells) carry oxygen, eosinophils are granulocytes involved in fighting parasitic infections and allergic reactions, and platelets are involved in blood clotting — none of these produce antibodies.