Infants in Developing and Developed Countries Grow About the Same

Infants in developing and developed countries grow about the same rate from birth to six months.Why are they similar?

A) Infants from developed and developing countries consume breast milk.
B) Infants from developed and developing countries start eating solid foods at birth.
C) Infants from developed and developing countries do very little to expend calories.
D) All infants have access to nutritious and well-balanced foods.