The workers insisted that they

The workers insisted that they _________ a free lunch every noon and the boss had to give in.A.be
没把握的别进.
A.be given B.being given C.will be to give D.wounld be giving

虽然楼主题目没给全,我想应该是be given(offered).（工人坚持要求每天中午提供免费午餐,老板只能让步.）这里的insist是坚持要求,应该用虚拟语气,“should + 动词原形” 省略should.
insist
1、意思是“坚持要”表示命令、要求,其后之宾语从句要用虚拟式动词原形
或者“should + 动词原形”
例：
They insisted that she (should) be invited.
I insist that you (should) see a doctor.
这种虚拟语气的用法除了“insist”还有：demand,suggest,order,propose.
2、意思是“坚持说,硬说”,其后宾语从句用普通时式,不用虚拟语气.
例：
She insisted that he was wrong.