[单选题]
Which hormone is secretehp)p+*5yb b jsup iy3j 7xi5d;b:hs 5vmwzp+w ub +/w6d by the gland labeled X?
A. Leptin
B. Thyroxine
C. Progesterone
D. Melatonin
参考答案: D
本题详细解析: Explanation:
Choice D is correct because the gland X is the pineal gland and it produces melatonin. Choice A is incorrect because leptin is produced by adipose tissue. Choice B is incorrect because thyroxine is produced by the thyroid gland. Choice C is incorrect because progesterone is produced by ovaries.
