This startle reflex (aka moro reflex) is/was present in us as newborns.
It's triggered when there's an unexpected reaction. Example: Loud noise, sudden movement.
The baby will tighten his/her body, fling out arms, sort of like giving him/herself a hug. It happens because the baby is trying to protect itself from harm.
It normally leaves thanks to the mother's care, normally 6 weeks after the newborn is born. 
        
             
        
        
        
The answer is B... im just making a guess so...
        
             
        
        
        
Answer:
a scrape being healed
Explanation:
cell reproduction is the process by which cells divide to form new  cells. each time a cell  divides it makes a copy of all its chromosomes, which are tightly coiled strands of DNA, the genetic material that holds the instructions for all life, and sends an identical copy to the new cell that is created.