I think the correct answer is the third option. Tonsils are large lymphoid nodules that are located in the walls of the pharynx. Tonsils are a part of the lymphatic system and is one of the fighters against infections and the first line of defense for inhaled or ingested pathogens. On their surfaces, they have specialized antigen cells which are called as M cells that would allow the uptake of antigens that is produced by pathogens. The most common condition that could happen to the tonsils would be tonsillitis. Symptoms of these are sore throat, fever and swollen tonsils. It can be caused by different viruses and bacteria.
