Answer:
Puberty is stimulating the development of his secondary sex characteristics.
Explanation:
Puberty is a biological, psychological and social phenomenon which generally occurs around 8-13 years of age in girls and 9-15 years of age for boys. This is a stage of many changes, especially in the body.
The secondary sex characteristics are traits that appear during this stage and they include the development of facial and chest hair, pubic hair and an enlarged Adam's apple in boys.
