I've never dated anyone. (Granted, I've interacted with girls on a general level at the very least before hahaha)
I would say a lot of it depends. For instance, I do not feel qualified to give advice on many straight up sex questions that are specific because I've never had sex. I don't know much in the area except for things from a psychological/scientific standpoint, so my advice in that area is not worth much.
However, I think I've definitely helped people in questions involving dating, even though I've never dated. I understand guy behavior so I can give perspectives from that side, and I know some stuff about girl behavior based on life experiences I've observed and interacted with. (Sometimes psychology classes I've taken and books I've had to read like "Why women have sex" come in handy for reference material too xD).
I have lived 20 years and have perceived the world all the time. I think that simply observing things have given me source material. A lot of things are question on human behavior, which I believe I can help with.
That being said, I would not claim to know "everything" about a gender of preference. Heck, I don't think I could say I know "everything" about guys since people differ person to person.
TL;DR; It depends. I picked C.