Puzzle of the week #129

Chess Diagram: 

[Event "Puzzle #129"][Date "2010.08.06"][Result "1-0"][SetUp "1"][FEN "4kb1r/2R2pp1/4b2p/4P3/8/8/PPP3PP/1K1R4 b k - 0 25"]25...Be7

Most of you have chosen to sacrifice a piece in the previous puzzle. This is very brave of you, but I truly wonder how many would actually do it in your real games. My doubt is based on the fact this sacrifice does not bring an immediate end to the game; at correct play Black should be able to hold on longer.
Black held on in the game (read the answer below carefully to see the best defence for Black) and reached this week's position. Things have changed a bit and the material imbalance (not the same pieces on both sides) creates an intriguing situation. Last move 25 by black is given. Your task is to choose the best continuation:
a) White started pushing the Queenside pawns to gain tempi before Black castles
b) White delayed pushing those pawns and continued concentrating on the same idea of keeping the Black King in the center. For both options you need to provide: analysis, conclusion and the best line you can put together
c) Does Black really has to castle in this endgame with no Queens? Please explain

Total available points for this puzzle is 30. The answers will be published next week together with puzzle #130.

Puzzle #128 solution:
Will start with the best answer of the week and will end by adding what happened in the game all the way to the position from puzzle #129. Rick's answer:
Line (a): see diagram
Material: We are equal, but Black has the Bishop pair, giving him a slight edge.
King safety: The White King has nothing to worry about, except maybe back rank mate in the future. Black must evacuate the center before White brings all his pieces onto active squares.
- White's isolated e-pawn is a long-term weakness
- Black is behind in development
- the White Knight would love to go to d6
- Bc4 is currently hanging
White plan is to try keeping Black behind in development while improving the position of his pieces.
Black's plan is to trade into the endgame, where Bishops can dominate Knights in this open position.
Line (b): see diagram
Material: Black has a Bishop for a pawn, but White is about to chomp away at Black's remaining Queenside pawns.
King safety: The White King might as well take a nap, for there is no danger at all. Black's King may look safe, but things aren't always as they seem...
- Trading Rooks on the d-file will eliminate Black's best defender
- Castling for Black will take two moves. Way too slow!
- Should this game reach an endgame, White will have a load of passed pawns on the Queenside
- Black will have a very tough game if he tries to keep his material advantage
White plans to get rid of Black's Queenside pawns followed by a deadly attack, since Black's King is stuck in the center anyways.

[Event "Puzzle #128"][Date "2010.07.30"][Result "1-0"][SetUp "1"][FEN "3rkb1r/pp3pp1/2p1b2p/4P1q1/2BQ4/2N5/PPP3PP/1K1R3R w k - 0 17"]{Line (a)} 17.Qxd8+ ({Line (b)} 17.Qxa7 Bxc4 18.Qxb7 Be6 (18...Qxg2 19.Rxd8+ Kxd8 20.Rd1+ Bd5 21.Nxd5 cxd5 22.Rxd5+ Qxd5 23.Qxd5+ {White wins}) (18...Rxd1+ 19.Rxd1 Be6 20.Qb8+ Bc8 21.Qxc8+ Ke7 22.Qd8+ Ke6 23.Qd7+ Kxe5 24.Qd4+ Ke6 25.Re1+ Kf5 26.Qe4+ Kf6 27.Rf1+ Qf5 28.Rxf5+ Kg6 29.Re5+ f5 30.Qxf5#) 19.Qxc6+ Rd7 20.Nb5 {Threatens Nc7+ followed by the capture on e6} 20...Qd8 21.Rd4 Qb8 22.Rhd1 Qb7 23.Rxd7! Qxc6 24.Nc7+ Qxc7 25.Rxc7 {See puzzle 129}) 17...Qxd8 18.Rxd8+ Kxd8 19.Bxe6 fxe6 20.Rd1+ Kc7 {This position looks equal and the game will probably result in a draw}

Correct solutions:
Owen, Rick - 20 points
Jeffrey, Karl - 18 points
Edwin - 16 points
Alex - 2 points

Owen - 95 points
Karl - 80 points
Rick - 59 points
Jeffrey - 51 points
Frank - 40 points
Edwin - 35 points
Alex - 16 points