Which of the following is a key hormone for female reproductive function?

Estrogen is a key hormone in female reproductive function as it plays a crucial role in various aspects of the reproductive system. It is primarily responsible for the development and regulation of the female reproductive system and secondary sexual characteristics. Estrogen is involved in the menstrual cycle, promoting the growth and maintenance of the endometrial lining, regulating ovulation, and influencing other reproductive processes. Additionally, estrogen impacts other bodily functions, including bone health and cardiovascular function, which are particularly significant in women.

While testosterone is also present in females and contributes to various bodily functions, it is not considered a primary hormone for female reproductive function. Insulin is involved in metabolic processes and regulates blood sugar levels but does not play a direct role in reproductive processes. Aldosterone, a hormone that regulates salt and water balance in the body, similarly does not have a direct influence on female reproductive function. Therefore, estrogen's primary and multifaceted role in reproduction and overall female health makes it the key hormone in this context.