I was shocked ______ the cruelty of Tom, a relative of my wife, who not only shouted ____ the

poor man begging for something to eat but also let his violent dog come _____ him. [ ] 

A. at; at; at

B. with; to; at

C. by; to; at

D. for; at; to

新公共行政学的主要贡献是什么？