God, some of these people make me wish I was a woman so I could go around aborting babies all willy-nilly just to piss them off.
Seriously, it's a woman's (or couple's) choice whether or not they want to have a child. Accidents can happen, and saying you shouldn't have sex if you don't want a kid is like saying you shouldn't drive if you don't want a semi to veer into the oncoming lane and turn you into hamburger. If you don't like abortions, don't have one. If you don't like meat, don't eat it. But don't try and pull out some bullshit A to C reasoning without even attempting to include B in there, and tell everyone they're murderers.
As for adoption, do you have any idea how hard it is to get a child put into a decent family where they won't get beaten or molested? It's like child rape roulette, and that's in the best case scenario where the kid actually gets adopted out and doesn't stay in a group home until they're 18. Some people don't like the idea of carrying a baby to term, then parting with it, possibly never knowing if it turned out okay. It's hard enough to have an abortion when the thing's still a parasitic organism, let alone willfully handing it over to strangers after spending nine months nurturing it.