Ladies: What makes you put a man in the "Friend Zone"?

One of my male listeners wanted me to put this out there because he has recently been placed in the "Friend Zone". If you aren't familiar with the "Friend Zone", here is the Wikipedia definition:

In popular culture, the "friend zone" refers to a platonic relationship wherein one person wishes to enter into a romantic or sexual relationship, while the other does not. It is generally considered to be an undesirable situation by the lovelorn person. One sign of being friend zoned is being told that they are "considering" the relationship, or if a friend needs to help by asking for them. Once the friend zone is established, it is said to be difficult to move beyond that point in a relationship.

I don't think women intentionally put men into the "Friend Zone", but I think it just happens because of chemistry, etc. There is always a reason for it to head down that road -- well, in men's minds at least. Here are the top reasons I see:

A) a nice guy but he is ugly?
B) you are into women yourself?
C) you like losers better?

The fellas want answers!