The question is incomplete as it does not have the options which are:
estradiol; pituitary gland
testosterone; hypothalamus
leptin; hypothalamus
leptin; pituitary gland
Answer:
leptin; hypothalamus
Explanation:
Gonadotropin hormones are the peptide hormones released by the nerve cells of the hypothalamus which stimulates the anterior hormone to release the gonadotropins like the LH and FSH hormones.
The GnRH hormone is released when the leptin, a protein hormone secreted by the adipocytes stimulates the GnRH neurons of the hypothalamus to release the hormone in both males and females.
