单项选择题

在Visual FoxPro中,统计KC表中按XF的不同分组各门课程的数量。在命令窗口应执行______

A.SELECT "统计" AS 类别,XF AS学分, COUNT (KH) AS 课程数 FROM KC GROUP BY KH
B.SELECT "统计" AS 类别,XF AS学分, COUNT (KH) AS 课程数 FROM KC GROUP BY XF
C.SELECT "统计" AS 类别,XF AS学分, COUNT (KH) AS 课程数 FROM STU GROUP BY XF
D.以上都不是