The correct option is A Hypothalamus
Somatostatin is produced by neuroendocrine neurons of the ventromedial nucleus of the hypothalamus. Somatostatin is released from neurosecretory nerve endings into the hypothalamo-hypophyseal system through neuron axons. Somatostatin is then carried to the anterior pituitary gland, where it inhibits the secretion of growth hormone from somatotrope cells.