After going to the zoo, the mall, and the movies, Cassie was sick of bending over backwards to entertain her nieces.

A、Cassiewasdoingverylittletoentertainhernieces.;
B、Cassiewasmakingsmalleffortstoentertainhernieces.;
C、Cassiewastryingveryhardtoentertainhernieces.;
D、Cassiewasnottryingatalltoentertainhernieces.