it's not black who has to respond to the benoni defense, that's why it's called a defense. anyway, pedantry aside, you should try to play e6, trade on d5, play d6 to prevent d6 from white, and then usually fianchetto your king bishop and try to expand on the queenside. White will probably come out of the opening with a moderate advantage, that's why I don't play the benoni.
What's the proper way for black to play against the Benoni defense?

White: Taimanov variation. Try to crush black with the e5 break at some point.
Black: Well, basically look to play b5 and gain queenside space while stopping white from playing e5.
These are general guidelines for the modern benoni, I don't know much about the other benoni's. I suggest you look through a database and then post some more speficic questions about certain lines that you find interesting.

It's a bit like a KID because black's main trump is his fianchettoed bishop. The dark squared bishop on the a1-h8 diagonal puts pressure on white's queenside, and black is trying for the ...b5 break. Also black tries to stop e5, which is white's plan in many variations. The light squared bishop is often restricted so ...Bg4 and ...Bxf3 can be a good plan, sometimes with the idea ...Re8, ...Ne5. ...a6, ...Rb8, ...Bd7 is another square for the bishop, although that can stop ...Nbd7. ..Na6 is another move, idea being ...Nc7 preparing ...b5. The queen can go to c7 or e7 but watch out in many Qe7 lines if white opens the e file with e5.

in the op diagram the black e pawn should be on e6 which is the starting point for the theme tourney as white to move
>:)
I'm currently playing on chess.com's latest thematic tournament (Benoni defense) and I'm getting thrashed in my games as black. I'm not doing very well as white, either, as evidenced by my hanging of a pawn in two separate games. Can someone please tell me what's the proper way to respond to the Benoni defense?