Among Atheists, Their Questioning of Religion Usually Began at What

Among atheists, their questioning of religion usually began at what period in their lives?

A) Not until they had children of their own, and had to explain why travesties in the world existed if there was a God.
B) Not until they were elderly, when they had tested religious principles, but still found that they remained sick, in poverty, or experiencing negative aspects of living.
C) During their college years, when the encountered new points of view that made them question what they had been told as children.
D) Usually fairly young, no later than their teens, when going to houses of worship seemed meaningless and boring to them.