【单选题】

The teacher has ------- catering to some students, but to retain his tenure, which effects only after a teacher has unanimously gratified his students, he offers his complaints -------.
A．(A) a hesitancy about ... carelessly

B．(B) an aptitude for ... sparingly
C．(C) a repugnance toward ... tactfully
D．(D) an enthusiasm about ... zealously
E．(E) a blitheness about ... carefully