The right answer is broadened shoulders in males
Secondary sex characteristics are different physical characteristics in girls and boys but are not present at birth.
Secondary sexual characteristics develop after puberty. Puberty refers to the acquisition of sexual maturity and reproductive abilities.
Puberty is triggered at the cerebral level by hormonal mechanisms involving in particular the ovaries, in the girl, and the testicles, in the boy.
It manifests itself in physically visible changes (= secondary sexual characteristics).