- A progesterone and estrogen
- B insulin and glucagon
- C thyroxine and TSH only
- D adrenaline hormone only
Correct answer: A. progesterone and estrogen
Explanation: When progesterone and estrogen fall, the uterine lining breaks down, causing menstruation.
Concept context
Male and female reproductive systems, gametogenesis, fertilization, implantation, pregnancy, and reproductive health.