a) Qc4 x d5+ Swopping of queens avoids attacks, but removes chances of winning 1 point
b) Qc4 - h4 Avoids swopping of queens but the reply Qc5+ is nasty. 0 points
c) Rf1 - d1 The queen is pinned, and so can only avoid the threat by Qxc4. Before retaking the queen White takes the black rook, with check Rxd8+, and coems out a whole rook up. 3 points.
d) Rf1 x f5 A pointless rook sacrifice, Black replies with first Qxc4 and then gxf5. 0 points