Which of the following is a female sex hormone? 

1. The ovaries secrete the estrogen. A minor quantity of estrogen is produced by the fat cells and the adrenal glands. 
2. The development of the reproductive and sexual systems, which typically starts when a female enters puberty, depends heavily on the hormone estrogen. 
3. After ovulation, the luteal phase starts. If fertilization doesn't take place, it lasts roughly 14 days and finishes right before a period. 
4. Estrogen concentrations are high over the majority of the luteal phase. Without estrogen, you run the danger of developing osteoporosis-causing weak bones later in life.

Hence, option B is the correct answer.