A:to be created
B:created
C:being created
D:creating
已知F1和F2分别是双曲线x2a2-y2b2=1a>0,b>0的左、右焦点,P是双曲线左支的一点, PF1⊥PF2,PF1=c,则该双曲线的离心率为( )