Puzzle of the week #326

Chess Diagram: 

[Event "Puzzle #326"][Date "2017.11.13"][Result "1-0"]1.Nf3 d5 2.c4 dxc4 3.e3 Nf6 4.Bxc4 Bg4

After only 4 moves both players have developed 2 pieces each. It is white to move and he had to decide on the best possible play. Your tasks:
a) What should white focus on to help him decide what to do?
b) Choose the best line you can think of, line giving white the winning advantage

Total available points for this puzzle is 15. The answers will be published next time together with puzzle #327.

Puzzle #325 solution:
Blackburne gambit trap. This week's best answer is by Lyvia:

[Event "Puzzle #325"][Date "2017.10.22"][Result "0-1"][SetUp "1"][FEN "r1bqkbnr/pppp1ppp/8/4N3/2BnP3/8/PPPP1PPP/RNBQK2R b KQkq - 0 4"] 4... Qg5 {to attack the undefended g2-pawn and also luring the knight to f7. If white plays g2-g3, I capture the free e5-knight} (4... Qe7 {Coby: I think it is this one because it attacks the knight and if he runs black win back the pawn}) (4... Qe7 {Joey} 5.f4 d6) (4... Qe7! {Eric} 5.Nxf7 Qxe4+ 6. Be2 Kxf7) (4... d5 {Blake} 5. exd5 Qf6) (4... Bd6 {Glyn} 5. Nd3 Qh4  6. g3  Qxe4+ 7. Kf1 Qxh1#) 5. Nxf7 {to attack the queen} Qxg2 {attacking the rook and threatening to win the queen} 6. Rf1 (6. c3 Qxh1+) Qxe4+ 7. Be2 Nf3#

Correct solutions:
Lyvia, Matthew - 15 points
Glyn, Coby, Joey, Eric, Blake - 2 points
Zheng Yu, Brian - 1 point

Lyvia, Matthew - 37 points
Coby - 24 points
Glyn - 20 points
Eric - 19 points
Justin, Ellie, Zheng Yu - 10 points
Brian - 7 points
Blake - 4 points
Jacey - 3 points
Darius, Lucas, Joey - 2 points


The f2/ f7 weak spot