Which best describes the location and role of the lymphatic system?

The lymphatic system is part of the Circulatory System and consists of lymph vessels, lymph nodes,organs like tonsils, thymus and spleen. The lymph vessels are structures having endothelial cells and attached to tissue called adventitia. Lymph nodes are bean shaped structure and located near the lungs as well as in the intestines and near the groin and armpit. Tonsils are organs having antigen cells called M cells. They are located at the back of one's throat and intersection of respiratory and digestive passage. Thymus is a lymphoid organ where the maturity of T cells happen and is located in the mediastinum of thoracic cavity, superior to the heart, posterior to sternum. Spleen is located above the kidney on the left side of the body which is then the largest organ in the lymphatic system. There are 2 main functions of the Lymphatic system. First is draining of interstitial fluid thus maintaining the fluid balance of blood and tissue. Second is fighting infection and intercede immunity.

It would be answer choice b (1975)