The correct option is C thymus
The thymus gland secretes peptide hormones called thymosins. The thymus plays a major role in the differentiation of T-lymphocytes which are responsible for cell-mediated immunity of our bodies. The thymus is also involved in the production of antibodies.
The thyroid gland secretes thyroxine and thyrocalcitonin.
The parathyroid gland secretes parathyroid hormone.
The pineal gland secretes melatonin.