Puzzle of the week #281

Chess Diagram: 

[Event "Puzzle #281"][Date "2015.09.20"][Result "1-0"][SetUp "1"][FEN "8/p7/8/1p6/1P2N3/2Pk4/P6K/8 w - - 0 1"]

Back in 2006 two top local juniors (white was from our club) were battling in this decisive endgame from the last round of the BC Junior Championship qualifier. Black managed to hold the draw and finish first. Your tasks:
a) What strategy did black use to hold the draw?
b) White can and should win this game. What is the winning idea?
c) Write the best winning line you can think of

Total available points for this puzzle is 25. The answers will be published next time together with puzzle #282.

Puzzle #280 solution:
Puzzle by GM Viorel Iordachescu. This King and pawns endgame is more complicated than it looks. Andrew, Coco and Cody get 10 points for giving it a try at home; all others with 5 points have managed to hold the draw for black during our class session. The correct solution is as follows:
White must do 2 things:
I. Create a passed pawn on the g-file (the h-file pawn cannot win)
II. Make sure the King is the front of the passed pawn to win the opposition

[Event "Puzzle #280"][Date "2015.07.22"][Result "1-0"][SetUp "1"][FEN "6k1/6p1/8/4K1P1/8/8/7P/8 w - - 0 1"]1.Kf5 Kf7 2.h3 Kf8 (2...g6+ 3.Ke5 Ke7 4.h4 Kf7 5.Kd6 Kg8 6.Ke6 Kg7 7.Ke7 Kg8 8.Kf6 Kh7 9.Kf7) 3.Kg6 Kg8 4.h4 Kh8 5.h5 Kg8 6.h6 gxh6 7.Kxh6 Kh8 8.g6 Kg8 9.g7

Correct solutions:
Andrew, Coco, Cody - 10 points
Jalen, Yakov, Aaron, Benjamin - 5 points