Which hormone is primarily produced in the ovaries and plays a key role in female reproduction?

Estrogen is primarily produced in the ovaries and is crucial for various aspects of female reproductive health. This hormone is responsible for the development of secondary sexual characteristics in females, including breast development and the regulation of the menstrual cycle. It also plays a significant role in the growth and maintenance of the female reproductive tissues, such as the uterus and vagina, and is involved in preparing the body for pregnancy.

While progesterone is another important hormone produced by the ovaries that helps regulate the menstrual cycle and maintain pregnancy, estrogen stands out as the key hormone promoting the establishment of female reproductive structures and functions. The other options, such as testosterone and insulin, have different physiological roles; testosterone is primarily associated with male reproductive functions and is present at lower levels in females, while insulin is involved in glucose metabolism and is not directly linked to reproductive processes. Thus, estrogen is the hormone primarily associated with female reproduction.