Annotated chess game

How can it be drawn if I can always choose to capture the pawn?

The duel would be drawn, not the game as a whole, since you would win with one of your other pawns  

What is being contemplated is an ending like this: w the game position with 4 pawns removed. Here, White to play, has to play to the 8th rank, else the pawn can never be saved. So 1.Kd6 Qe8 2.Kc5 Qc8, where the Queen waits until the Black King comes up. Instead, the draw might run: 1.Kd8 Qd5+ 2.Ke8 Qc6+ 3.Kd8 Qd6+ 4.Kc8 Kf4 5.Kb7 Qd7 6.Kb8 Qb5+ 7. Ka7 Qc6 8.Kb8 Qb6+ 9.Ka8! ... and White can allow the c-pawn to promote - a draw; or take it at once for a Stalemate. By the way, the pawn on the seventh is not a gimme: it works only for a-, c-, f-, and h-pawns, and that's because of the Stalemate tricks available. Even then, the idea won't work if the enemy King is close enough, which can mean, for example, checkmate can be delivered even if the pawn does promote!