Many of his colleagues _____ him when it became known how he had abused his position in the company

Many of his colleagues _____ him when it became known how he had abused his position in the company.
A. called on B. convinced of C. confirmed D. turned against
为什么选D？请翻译整句 谢谢

many .many of用法 While _____ in Australia, he met many of his old friends. many of 的问题 some of his books -------- His mother grows many vegetables in his ____(菜园）. many 与 a lot of many 与many of区别和用法是什么？ masses of & a large amount of & many of的区别 the husband survived his wife ( for / by )many years. ____years ago,a man took many animals to his home.