7. A quickrule of thumb for the space required to run PROC SORT is:
A. two times the size of the SAS data set beingsorted.
B. three times the size of the SAS data set beingsorted.
C. four times the size of the SAS data set beingsorted.
D. five times the size ofthe SAS data set being sorted.
这道题选A 还是C 请会的坛友给解答一下,并稍微解释一下。