He made up his mind to devote his life ______ the river ______ polluted.

A．to prevent; to be

B．to prevent; from being

C．to preventing; to be

D．to preventing; from being

A女士持有拟发行上市B企业30%的股份，A女士的丈夫C先生为D证券公司的保荐代表人，则C不得担任该项目的保荐代表人。( )