This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Unknown
A mother brings her 5-month-old infant to the physician for a well-baby checkup. At this time the physician should expect to see 
Select and explain. 
A. Stranger anxiety, B. A pincer grasp, C. Object permanence, D. Sitting with support
D: Sitting with support
Answer: D: Sitting with support 
Explanation: Sitting with support is normally seen in a 5-month­old infant. Stranger anxiety (fear of unfamiliar people) does not appear until approximately 7 months of age. A pincer grasp (using thumb and forefinger) appears at approximately 9 months of age, whereas object permanence (the ability to maintain a mental represen­tation of an object although it can no longer be seen) occurs between 12 and 18 months of age. Using mean­ingful words is not commonly present until at least 12 months of age.