Which of the following changes occur in females at puberty?

• Puberty means the maturation of human sexual characteristics. 
• Like Ovulation, this is the process of releasing an egg or ovum every month in females.
• This is exclusive to females only. The option of deepening of voice is seen in males at the onset of their puberty.
• Because of the hormone estrogen, the females experience a broadening of the pelvis to help widen the birth canal.

Hence, option D is the correct answer.