请问一下SAS Adv 153题(A00-212)的第15题:

QUESTION 15
Which SAS procedure changes the name of a permanent format for a variable stored in a SAS data set?
A. DATASETS
B. MODIFY
C. FORMAT
D. REGISTRY

Correct Answer: A


我的问题是：datasets 具体是怎么做到 change the name of a permanent format for a variable stored in a SAS data set的? 编程上是怎么实现的?


多谢～