The American Revolution was mainly cause by colonial opposition to the British attempt to place greater control over the colonies as well as to make them repay the crown for defending them during the French and Indian war.
I can't imagine what A and B would contribute to life expectancy.
C is a bit of a different choice. It would, I think, decrease the life expectancy of the general population depending on which country is allowed to come into America.
The best answer to an increased life expectancy would be D. It is certainly true.
D <<<<< Answer
