Any survey of people’s religions will have a category for people to answer “no belief/atheism”. OP seems interested in what people believe and what led them to have that belief. I don’t think answering with Atheism is going against that.
This one does not have a category for not being religious. It only asks what religion people belive in.
I’m totally down for the atheist response, although it technically isn’t a religion in itself as much a position on whether you believe in a deity or not. A N/A response is totally cool in my book and I actually appreciate it. But def would prefer if people would describe what led them to it in more depth