During a Well-Baby Checkup,the Mother Expresses Concern That Her 2-Month-Old

During a well-baby checkup,the mother expresses concern that her 2-month-old infant is not able to hold her head up when she is pulled to a sitting position.Which of the following responses by the nurse is appropriate?

A) "This is not a concern because head control is usually not achieved until 4 months of age."
B) "You shouldn't be trying to pull your baby up like that until she is older."
C) "This is a concern because head control should be achieved by this time."
D) "This is a concern because it indicates possible nerve damage to the neck muscles."