A nurse is teaching about nutrition guidelines to a parent of a newborn. Which of the following statements by the parent indicates understanding of the teaching?

"I should start solid foods when my baby is 3 months old."

"I should wait to begin fluoride supplements until my baby is 4 months of age."

"I should wait to give fruit juice until my baby is 6 months of age."

"I should introduce cow's milk when my baby is 9 months old."