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
By 2 week of age, infants normally show all of the following signs EXCEPT 
Select and explain. 
A. Copying facial expression, B. Stepping, C. Palmar grasp, D. A negative Babinski reflex
D: A negative Babinski reflex
Answer: D: A negative Babinski reflex 
Explanation: By 2 weeks of age, infants show stepping, palmar grasp, the rooting reflex, and the copying of facial expressions. The Babinski reflex is normally positive until a child is approximately 12 months of age.