GIRL A. simply because I don't trust girl B. GIRL b tend to be girls who flirt even in relationships and need validation constantly. Plus girl when I picture a girlfriend I imagine everyday life and I'd love to see my girlfriend in type A clothes and B clothes in the bedroom only. When it comes to the gym girl b is what I'd call a show off and vain. You don't need to be that naked to lift weights. Yoga pants and a normal top is the way to go.
Girl A for me but it has nothing to do with being covered up more, that doesn't matter to me. Girl A looks (and I know I'm judging but it's what I see by looking at them), she looks nicer, more caring etc. Girl B looks like she WAY too into herself, has a chip on her shoulder maybe even? A "bitch" for a lack of a better word. Looks like she has lip injections which if so is a turn off. She has some muscle definition which is also a bit of a turn off. Just generally doesn't look like she cares about anything or anyone but herself. If nothing else, has an attitude that would be a turn off.
I am trying to not to judge a girl too much only based on her clothes, after all a true slut is a girl that had many dicks on her, either she dress modesty or not, and some sluts are in fact trying to play innocent, but with that said, from my experience I know that girls who dress more revealing are more likely to be slutty, and one night stand is not what I am looking for, but the only way to know for sure is to talk with the girl or/and to make an investigation on her. I am not going to laugh at girls who dress revealing, they do look more sexy, but they don't look very shy, to say the lest, for better and worse.
B attracts more attention. She (they) would be the first option if a dude was looking for a good fuck. A is what more guys will go for. Mostly because the chick looks way less intimidating and more like someone who isn't just dtf and has nothing more to offer. Whether it's true or not is TBD. I know plenty of girls who look closer to b, but they're some of the most down to earth and nicest girls I know... At least to me