The correct answer is A. Spleen.
The spleen is an organ in the human body that is located in the upper left abdomen. It is part of the lymphatic system, which helps to fight infection. The spleen also helps to remove old red blood cells from the blood.
The pituitary gland is a small, pea-sized gland located at the base of the brain. It is often called the “master gland” because it produces hormones that control many other glands in the body.
The thyroid gland is a butterfly-shaped gland located in the neck. It produces hormones that regulate metabolism, growth, and development.
The adrenal glands are two small glands located on top of the kidneys. They produce hormones that help to regulate the body’s response to stress, as well as hormones that regulate blood sugar levels.
The spleen is not an endocrine gland because it does not produce hormones.