Which statement indicates that the parents have understood the teaching?

The correct answer is A because it shows the parents understand the teaching by acknowledging the specific needs of their baby for Vitamin D and iron supplements. Choice B is incorrect as it includes Vitamin C unnecessarily. Choice C is incorrect as it suggests providing no supplements at all. Choice D is too vague as it only mentions iron supplements without considering other essential nutrients. Choices E, F, and G are not provided, so they are irrelevant. Overall, choice A is the most accurate and comprehensive response indicating the parents' understanding of the teaching.