a combination of all 3, depending on time of day, current situation, how well i know her........
i cannot appoach someone i do not know yet, either becouse she will have her friends around her (scary), or becouse she is standing alone with a 'just stay away' air around her, which i will respect
with some alcohol or heavy peer pressure, i might be able to turn the situation on #1 into a #2, but then i wil be so awkward that it is failed from the start, i will feel like i am wasting her time with a useless aproach sentence, and even if i do get to converse, the only way i know to get a bit further is just blurting out something like "you date me?" (yeah, drunk :S)
with girls i already know, i'm the posterboy for #3, not wanting to risk the few friends i have, i will not make a move, even if pressured by perope around me, even if the girl in questions best friend tells me to go for it, i wont. i would need a direct invitation of the girl in question; evne then i'd hesitate...
then there is also #4 that i identify with; the clueless one.
there have been situations where woman heve thrown themselves at me, and i just completely misse dor misread the situation, thinking the "kiss me now" bodylanguage ment "get the hell away from me"...