Correct Answer: thymosin

Solution : The correct option is thymosin.

Thymosin is the hormone generated by the thymus gland, which is an important component of the immune system. Thymosin is essential for the growth, maturation and function of immune cells, especially T lymphocytes. T cells are a kind of white blood cell that is important in the body's adaptive immunological responses. Thymosin aids in the development of a broad and effective T cell repertoire capable of recognising and combating infections, illnesses and other risks to the body.