During adolescence growth spurt occurs in both males and females, so growth velocity increases both in girls and boys. There is some weight gain also due to fat deposition in certain body parts of girls and due to bone maturation in male and female. About half of ideal adult body weight is gained during adolescence. Cracking of voice occurs in male due to testosterone hormone. It is a remarkable change in boys during adolescence.

So, the correct answer is 'Cracking of voice'