Correct Option: C

An antibody (Ab), also known as an immunoglobulin (Ig), is a large Y-shaped protein produced by B-cells that is used by the immune system to identify and neutralize foreign objects such as bacteria and viruses. Each antibody is produced by lymphocytes (specialized white cells) as a result of exposure to specific chemical substances called antigens usually on the outside of an invading organism. This is called the antigen-antibody reaction.