Final answer:
The appropriate response in the care plan for a parent who is experiencing guilt in this situation would be to clarify misconception about the illness.
Step-by-step explanation:
The appropriate response in the care plan for a parent who is experiencing guilt in this situation would be to A. Clarify misconception about the illness. It is important for the parent to understand that croup is usually a viral infection and not something that could have been completely prevented by earlier medical intervention. By clarifying this misconception, the nurse can help alleviate the parent's guilt. It is also important to provide emotional support and reassurance.