What is the pivotal change in the hypothalamic-pituitary-gonadal axis that defines the onset of puberty in the male?
A. Suppression of luteinizing hormone (LH) and follicle stimulating hormone (FSH). B. Reduced synthesis of estradiol by extragonadal tissue. C. Enhanced synthesis of androstenedione by extragonadal tissue. D. Increased frequency and amplitude for release of gonadotropin releasing hormone (GnRH). E. Increased release of growth hormone releasing hormone (GHRH) by arcuate neurons of the hypothalamus.