This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Impoant Terminologies and Primitive Neonatal reflexes, Subject name: Pediatrics
Which of the following components of Moro's reflex is the earliest to appear? 
Select and explain. 
A. Opening of hands, B. Abduction of upper limbs, C. Adduction of upper limbs, D. Movement of trunk
A: Opening of hands
Answer: A: Opening of hands 
Explanation: Moro's reflex: Component of Moro's reflex Gestational age of appearance Opening of hands 28 weeks Extension & abduction of upper limbs 32 weeks Anterior flexion of upper limbs 37 weeks