The testes at the inguinal ring descend to scrotum at 12 weeks.
The bladder and urethra separate from the rectum at 12 weeks.
The kidneys are in position at 16 weeks with typical shape and plan.
The nostrils reopen and primitive respiratory-like movement begins at 24 weeks.
Number 3 is correct.
Rationale: The kidneys are in position at 16 weeks with typical shape and plan. Testes descend to the scrotum at 24 weeks. The bladder and urethra separate from the rectum at 8 weeks. Primitive respiratory responses begin at 20 weeks.