The onset of adolescence, when hormones cause sex organs to mature and humans become capable of reproduction is called puberty. The correct option among all the options given in the question is option "D". For the girls, this is the process that usually happens between the ages of 10 years and 14 years. In case of boys, this process happens between the ages of 12 years and 16 years.
It causes a number of physical changes among boys and girls.
