I actually recall some study about this. Though romance novels idolize option A, it doesn't really seem to happen as people tend to be attracted to what they're familiar with. I'm sure there are exceptions, but option B matches my own experiences, as I've only been in a long term relationship with people whom I have mostly similar personalities with. The key word here is "mostly", being in a relationship with your clone would be rather boring, but I do suspect most successful couples tend to share some core similarities.

Though as I'm single I can't say I've been in a "lasting" relationship.

I've seen C happen, but it seems that in that case people are desperate to be in a relationship and need to work on it. Also it's worth nothing that (at least to me) this seems to be a special case with relationships. In terms of friendships I'm pretty good friends with a lot of people who in terms of personality and interest are almost my exact opposites.