__ is our belief that improvement in health care will lead to a stronger,more prosperous economy.(2006浙江)

问题描述:

__ is our belief that improvement in health care will lead to a stronger,more prosperous economy.(2006浙江)
A.As B.That C.This D.It
为什么选A?我以为是第四个,
”改为“that”,就选it,把其他几项都给我解释一下,还要这句的翻译

应该选D,你应该相信自己.
如果把“,”改为“that”,就选it?
还是看不懂,逗号前面和后面就是并列,在句中的成分一样,根本对选什么没有影响.