This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous, Subject name: Medicine
Which one of the folloiwng hormonal level is decreased after Intracranial irradiation? 
Select and explain. 
A. Prolactin, B. ACTH, C. Growth hormone, D. Gonadotropin
C: Growth hormone
Answer: C: Growth hormone 
Explanation: (C) Growth hormone # Endocrine dysfunction frequently follows exposure of the hypothalamus or pituitary gland to therapeutic radiation. Growth hormone is the pituitary hormone most sensitive to radiation therapy, and thyroid- stimulating hormone is the least sensitive; ACTH, prolactin, and the gonadotropins have an intermediate sensitivity.