提个英语问题,The headmaster has always got some------from the stud

表示 抱怨,抗议,怨言时可数
表示 抱怨的缘由时不可数
1.抱怨;抗议;怨言;抱怨的缘由[C][U][(+about/over/against)]
There is no real reason for complaint.
没有什么可抱怨的理由.
2.【律】控告;控诉[C][(+against/with)]
The storekeeper signed a complaint accusing them of shoplifting.
店主签署了控告书,指控他们在店里扒窃货物.
所以是complaints