Final answer:
The purpose of thymosin is related to the development and differentiation of T cells within the immune system, making option (A) the correct choice.
Step-by-step explanation:
The hormone thymosin has a specific role in the body, particularly in immune system function. A key purpose of thymosin is to contribute to the development and differentiation of T lymphocytes (T cells), which are crucial cells in the immune system for fighting off pathogens. Option (A) T cell development and differentiation correctly describes the purpose of thymosin.
Regarding the other options: (B) refers to functions related to the reproductive system and not thymosin, (C) involves the regulation of hormones like insulin and glucagon which is unrelated to thymosin, and (D) increasing blood glucose levels is a function of hormones such as glucagon, not thymosin.
So, the correct answer is option a.