I think that if you are too young to support the baby, not financially stable or just the fact that they do not want a child, and will not love it then abortion is the best option.
If you get pregnant, then you should only have the baby - if your prepared to give your love, your time and money towards the baby.
If the baby isn't going to have a good life thats worth living, its better off not having the life - besides during the time of the abortion the fetus is not actually human, which has already been covered.