If I have to pick one answer, I'd say F.
But like a lot of people I'm sure, it's not as clear-cut as that. It was a mixture between being mad at my god (after my allegedly just god let or made two close family members suffer for years and die from cancer); reflecting about that, what my religion taught me growing up, and about religion(s) in general, and consulting the Bible, other holy books, and arguments against.
If it weren't for all of these I don't know if I would have become an atheist. But because other people (including people in my family) were faced with similar circumstances and aren't atheists, I think it obviously had to be me gradually coming to realize the truth more than any one other thing. God just doesn't make sense.