It is easy to be grateful for the good things a life of rich fulfillment comes to those

问题补充：

It is easy to be grateful for the good things, a life of rich fulfillment comes to those who are also thankful for the setbacks.

A. that

B. which

C. while

D. when

答案：

A. that

B. which

(答案→)C. while

D. when

解析：句意：感激美好的事物简单，然而，有成就的人生属于那些感恩挫折的人。此处while是并列连词，前后是对比关系。故选C。