We all know that, _____ , the situation will get worse[ ]

A. if not carefully dealt with            

B. not if dealt carefully with

C. if don't deal with carefully            

D. not if carefully dealt with

关系模式规范化过程中，若要求分解保持函数依赖，那么模式分解一定可以达到3NF，但不一定达到 【12】 。