Answer - D. Were in Search for food to eat.
Reasoning - As ice age and resistant of water became changing in ponds and lake the resource of food started to deplete so evolution became a evolving for creatures aka reptiles.
It’s c direct effect on the pancreas hoped that helped
It would be A. That’s the point of a flu shot. U inject the virus to make your body know it’s bad and when It comes along again to fight it hard.