The correct answer is B. WBC.
White blood cells (WBCs) are the cells in the blood that fight infection. They are also called leukocytes. There are many different types of WBCs, each with a different function. Some WBCs engulf and destroy bacteria, while others produce antibodies that attack bacteria or viruses.
When a foreign body enters the blood, the WBCs are the first to respond. They travel to the site of the infection and release chemicals that kill the bacteria or virus. They also help to remove dead cells and debris from the area.
RBCs, or red blood cells, are the cells in the blood that carry oxygen to the tissues. They are not involved in fighting infection.
Platelets are the cells in the blood that help to stop bleeding. They do this by forming a clot at the site of the injury.
Cytoplasm is the jelly-like substance inside cells. It is not involved in fighting infection.
In conclusion, the correct answer is B. WBC. WBCs are the cells in the blood that fight infection. They are the first to respond when a foreign body enters the blood.