The correct answer is B. Lymphocyte.
Lymphocytes are a type of white blood cell that are responsible for the body’s immune response. They produce antibodies, which are proteins that help to fight off infection. When a vaccine is administered, it exposes the body to a weakened or inactivated form of a pathogen. This triggers the production of antibodies, which will then be able to recognize and fight off the pathogen if it is ever encountered again.
Granulocytes are another type of white blood cell, but they are not responsible for the production of antibodies. They are involved in the body’s inflammatory response and help to fight off infection by engulfing and destroying pathogens.
Erythrocytes (red blood cells) are responsible for carrying oxygen throughout the body. They do not play a role in the immune response.
Platelets are involved in blood clotting. They do not play a role in the immune response.