It's better to say that there are some hypotheses towards that end. Daniel Dennett is the major promoter of such ideas if you want to investigate further, but there's no actual evidence to suggest so. Granted, there's no evidence yet against it either, but burden of truth and parsimony and all that. (Dennett claims that the involvement of nanolevel structures in the brain implies a quantum basis for consciousness, if I remember correctly, but that's just supposition on his part.)
Even if it were true, though, I'll suggest the thing that moved me off of that as a resolution: if a person's selection of an action is based on a random flip of a coin or roll of a die somewhere at the submolecular level in their head rather than based on personal preferences or experiences and a weighted consideration of the options and their consequences, can you really consider that to have been them "making a decision"?