The answer is; 12
Puberty age is between the ages of 10 and 4 for girls and 12 – 16 for boys. During this period, there is rapid development and changes to their bodies. It is also during this age that girls and boys discover they are different from each other. Girls begin to menstruate and grow breasts at this age.
Option B, 12
All the characteristic changes mentioned in the case of Gabriel are the physical and biological changes that a boy experience at the age of puberty.
The puberty in boys starts by the age of 12 in most of the cases and in some cases it starts between any time period of 12 to 16 years.
Since Gabriel is experiencing puberty changes, his age would be somewhere between 12 to 16.
Hence, option B is correct