Puzzle of the week #335

Chess Diagram: 

[Event "Puzzle #335"][Date "2018.02.12"][Result "1-0"][SetUp "1"][FEN "8/2k3n1/8/4rp2/6p1/B5P1/5P2/R4K2 w - - 0 1"]

After a long battle the game has reached this normal looking position. Material is equal and white to move has to decide what to do. Your tasks:
a) Which piece is better: the Bishop or the Knight? Why?
b) Which King is safer?
c) Can you find the nice trick white can use to win the game?

Total available points for this puzzle is 20. The answers will be published next time together with puzzle #336.

Puzzle #334 solution:
FM Marius Ceteras, 2007. This week's best answers are by the top scorers. Quite a few missed how black escapes into an equal position if white exchanges 1. Bxc5. The answers:
a) White is behind 2 points: has a Bishop for a Rook
b) White should use the pin on Rc5; it has 2 attacks for 2 defences and can bring another attacker to win material

[Event "Puzzle #334"][Date "2018.02.04"][Result "1-0"][SetUp "1"][FEN "2r3k1/q5pp/4p3/2rp1p2/1p1B1P2/1P1QP3/P1R3PP/6K1 w - - 0 1"]1. Qb5 (1. Rxc5? Rxc5 {White cannot bring another attacker on the c5-Rook}) (Bxc5? Rxc5 2. Qd4 Rc7 {Move missed by many. The position is equal}) Rxb5 (Rxc2 2. Bxa7 {white is ahead in material more than before}) 2. Rxc8 Kf7 3. Bxa7 {white is up a piece}

Correct solutions:
Aiden, Joey, Mengbai, Eric, Matthew - 20 points
Jacey, Coby, Lyvia, Glyn, Lucas - 11 points
Brian - 10 points
Zhengyu, Itamar - 7 points
Blake - 1 point

Lucas - 7 points for puzzle #333
Glyn - 2 extra points for puzzle #333

Matthew - 70 points
Eric - 67 points
Lyvia - 60 points
Coby - 51 points
Zhengyu, Aiden, Joey - 43 points
Jacey, Mengbai - 41 points
Glyn - 40 points
Brian - 38 points
Itamar - 28 points
Lucas - 24 points
Blake - 21 points
Walter - 10 points
Darius - 8 points
Chris - 3 points