A nurse is caring for an 18-month-old infant who screams when the parent leaves the room. The parent seems very upset and says, "I don't understand why my child is so upset. I've never seen my child act this way before." Which of the following statements should the nurse make?

Rationale: A. A common reaction to strange surroundings is true but too general and does not educate the parent about developmental expectations. B. Children around 18 months often experience separation anxiety, which is a normal stage of development. Explaining this to the parent and offering strategies like rooming-in helps reduce anxiety for both child and parent. C. Sickness alone does not fully explain separation anxiety; developmental stage plays a primary role. D. Overstimulation may exacerbate distress but is not the primary reason for separation anxiety at this age.