All the people present agreed that the matter required .
A. to look into
B. being looked into
C. to be looked
D. looking into
网友回答
A. to look into
B. being looked into
C. to be looked
(答案→)D. looking into
解析：考察固定结构。Sth require doing/to be done某事需要被做；结合句意可知D正确。句意：在场的所有人都同意这件事情需要进一步调查。