What stimulates the gonads in the male at 8 weeks to secrete testosterone –
During embryogenesis, In male embryo, at the 6-7 week of gestation, secretion of a first anti-mullerian hormone (also k/o Mullerian inhibiting substance) causes regression of Mullerian duct.
Then at 8-12 week, under influence of Placental HCG, testes started producing testosterone.
Inhibin from corpus luteum
GnRH from hypothalamus of baby
Placental HCG
All of above