Final answer:
Fertility and ovulation are synchronized mainly through hormone injections, using synthetic hormones, which include progesterone and estrogen. Hormone injections control the menstrual cycle and trigger ovulation to coincide with fertility treatments such as IVF. The correct answer is (option D) hormone injections.
Step-by-step explanation:
Fertility and ovulation synchronization are mainly achieved through the use of hormone injections or hormonal methods. These methods involve synthetic hormones such as progesterone, which may be used in combination with estrogen to suppress the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from the hypothalamus. This inhibition ensures that an egg is not available for fertilization, thereby controlling the timing of fertility.
Hormone injections can be administered to regulate the menstrual cycle and trigger ovulation at a specific time, which is particularly useful in assisted reproductive technologies such as in vitro fertilization (IVF). The hormones injected, which can include FSH and LH, help to mature the ovarian follicles and release the egg, synchronizing ovulation with the timing of IVF or other fertility treatments.