When A serves, the ball first hits the net post and then his side of the table from where it spins over the net. Before it can bounce on X’s side of the net, x catches it, above the table. The umpire should award a
选项：

A: point to X because A did not make a good service
B: let, because the ball was obstructed in a net-cord service which was otherwise good
C: point to A because X obstructed the ball
D: point to A because X prevented A from making a good service