Question

multiple choice question
the thymus secretes a hormone that
raises blood calcium levels
regulates the development of t lymphocytes
decreases blood glucose levels

Explanation:

The thymus secretes thymosin. Thymosin is crucial for the development and maturation of T - lymphocytes (T - cells). T - cells are a type of white blood cell that play a vital role in the immune system.
Calcitonin (from the thyroid in some cases, but not the thymus) and parathyroid hormone (from the parathyroid glands) are involved in regulating blood calcium levels. Insulin (from the pancreas) decreases blood glucose levels.

Answer:

regulates the development of T lymphocytes