A 9-month-old infant has developed two teeth since the 6-month checkup. The local water supply contains fluoride. What will the primary care pediatric nurse practitioner do to promote healthy dentition at this visit?

Apply sodium fluoride varnish to the infant's teeth.

Teach the parents how to brush the infant's teeth with fluoride toothpaste.

Encourage the parents to make an initial dental appointment.

Prescribe oral fluoride supplementation.