An Amazing Move
In order to immobilize both of Black's e2 and d1 knights, White has to maintain his on f5. White needs to avoid knights moves that come with checks. So, the g6, e6, c6, h5, (f5), d5, b5, g4, e4, c4, a4, h3, d3, b3, c2, a2, and b1 squares are off-limits for the white king.
Black only has his black pawn. The correct move is 1...a6! If the white king goes on the 7th rank, it will never catch up with the pawn, so White would need to move its knight to stop promoting, in which case Black's king would escape and Black would win.
e6, c6, and d5 are already off-limits. If 2.Ke5, then the king can't progress on d4 because of the e2 knight, and would need to go back on d6 after 2...a5, and it would be too late. If 2.Kc5, then 2...a5! and the white king just can't progress the pawn promotion anymore without freeing the black king : the pawn controls b4, the b2 knight controls d4, 3.Kc4 is refuted by 3...Nb2+ and 3.Kb5 is refuted by either 3...Nec3+ or 3...Ndc3+.