句子意思是：警方已经呼吁有消息的人们前来与他们交流.
正确答案是B appealed to 呼吁,恳求、 appeal to sb to do 呼吁某人干某事
如：The police appealed to the crowd not to panic警方向群众呼吁不要惊慌.
事实上appeal to sb to do意思近似于call on sb to do ,,但是不能用call for sb to do结构
call for sth 需要.、 call for sb 去接,去拜访某人
如：The situation calls for prompt action / I'll call for you at 7 o'clock.