求教一道语法题~~~

Rainbeauty

The organic food industry has organized a successful grassroots campaign—using Web sites, public meetings, and also mass mailings—that have convinced the Department of Agriculture to change the proposed federal regulations for organically grown food.
A.    using Web sites, public meetings, and also mass mailings—that have convinced
B.    using Web sites, public meetings, and mass mailings—that has convinced
C.    by using Web sites, public meetings, and mass mailings—in convincing
D.    by the use of Web sites, public meetings, as well as mass mailings—that convinced
E.    which used Web sites, public meetings, and mass mailings—in convincing
解释说有固定搭配：campaign for/against 这样的话，convinced动作发出者就应该是Web sites, public meetings, and also mass mailings。。。就应该是have convinced为什么要has convinced 呢？破折号到底是干什么的？

geegee

a campaign 应该是has convinced...,using a,b and c只不过是进步不解释了organise的方式方法吧...

cnie

INDUSTRY HAS ORGANIZED CAMPAIGN THAT HAS CONVINCED...TO
破折号解释说明CAMPAIGN
你说的CAMPAIGN AGAINST/FOR的内容是TO以后的内容，REGULATION CHANGE