The Nurse Is Performing a Well-Baby Check on an Infant

The nurse is performing a well-baby check on an infant at 6 months of age. The mother shares that the infant sometimes seems unhappy. Which question is most important for the nurse to ask the mother?

A) "Is it easy to make the baby laugh if he seems unhappy?"
B) "Can you cheer him up by playing with his favorite toys?"
C) "Do you ever remember feelings of being depressed or sad?"
D) "Are you noticing any problems with him eating or sleeping?"