After a long discussion about the advantages and disadvantages of the plan they finally

问题补充：

After a long discussion about the advantages and disadvantages of the plan, they finally a conclusion it is relatively practical.

A. came up, that

B. came into, /

C. came over, /

D. came to, that

答案：

A. came up, that

B. came into, /

C. came over, /

(答案→)D. came to, that

解析：句意：对于这个计划的利与弊长时间的讨论，他们最终得出了一个结论，这个结论相对可行。Come to a conclusion是固定用法，意思是得出结论。这个句子含有一个同位语从句，且引导词在从句中不作任何成分，也没有实际意义，所以用that，可知选D。