How to come out?

I want to come out to the people in my friendship circle, but I'm not sure whether I should come out to them individually or tell them all at once. I think that all of them will accept me, but I want to minimize the damage in case something goes wrong.

Here's a little background information: there's 3 people, let's just call them Girl A, Girl B and Guy.

~ I know that Girl A will accept me because she dated a gay guy once and I think she's still friends with him.

~ I get along best with Girl B and I think that she'll also accept me. She is the type that thinks that guys should show their emotions and she's seen the slightly more feminine side of me. Though she thinks/assumes I'm straight and she used the word gay in the meaning of stupid once :dry:

~ The guy is a total mystery to me, but we've sorta known each other before we met others in our group. We've speculated about a person possibly being gay and I didn't see any negative signs from him (nor from my other friends). He did call my umbrella gay once, which I thought was kinda funny (it was light blue and apparently it was a women's umbrella :lol.

So what should I do? First come out to Girl A because she's the one who's most likely to accept me, Girl B because I know her slightly better, Guy because I've known him the longest or come out to all of them at once? It might be a bit more difficult to talk to them individually because we're all studying the same thing and we hang out most of the time during school. And let's say I come out to all of them at once. If I happen to get a negative reaction, could the other's positive reactions have an influence on him/her and make that person more likely to accept me?