user9584: [FEN "8/R7/4k3/3nP3/3p4/P2K4/1P6/8 b - - 0 1"]

What is the best move for black?

user4418: Unless your opponent is really, really weak (and presumably you are even weaker since you've got a completely lost position) then "resigns" is the best move.
If you want to see if your opponent knows how to win the position then you could try Kxe5 when black will play Ra5, pinning the knight, exchange off the knight and then push the a and b pawns and queen one of them. Other moves by you are equally futile.
If your opponent was good enough to get this completely won position then he is probably also good enough to know that he just needs to exchange his rook for your knight to have a trivial win and there is little you can do to stop this.

user14079: At tournament level, Black can safely resign. If you wanna play some more moves, taking a pawn with 1...Kxe5 looks reasonnable.
I see no trick with stalemate nor with the d-pawn, e.g. 1...Nf4 2.Ke4 [2.Kxd4+-] d3 3.Kxf4 d2 doesn't promote because of 4.Ra6+ Ke7 5.Rd6 +-
1...Ne7 can be a trap [2.Kxd4?? Nc6+ with a probable draw (or not even, see Annatar's comment)] but it is easily beaten by 2.Ra6, 2.b4 or the simple 2.Rxe7.

9584: <pre><code>[FEN "8/R7/4k3/3nP3/3p4/P2K4/1P6/8 b - - 0 1"]
</code></pre>

<p>What is the best move for black?</p>
 4418: <p>Unless your opponent is really, really weak (and presumably you are even weaker since you've got a completely lost position) then "resigns" is the best move.</p>

<p>If you want to see if your opponent knows how to win the position then you could try Kxe5 when black will play Ra5, pinning the knight, exchange off the knight and then push the a and b pawns and queen one of them. Other moves by you are equally futile.</p>

<p>If your opponent was good enough to get this completely won position then he is probably also good enough to know that he just needs to exchange his rook for your knight to have a trivial win and there is little you can do to stop this.</p>
 14079: <p>At tournament level, Black can safely resign. If you wanna play some more moves, taking a pawn with 1...Kxe5 looks reasonnable.</p>

<p>I see no trick with stalemate nor with the d-pawn, e.g. 1...Nf4 2.Ke4 [2.Kxd4+-] d3 3.Kxf4 d2 doesn't promote because of 4.Ra6+ Ke7 5.Rd6 +-</p>

<p>1...Ne7 can be a trap [2.Kxd4?? Nc6+ with a probable draw (or not even, see Annatar's comment)] but it is easily beaten by 2.Ra6, 2.b4 or the simple 2.Rxe7.</p>
