删除计算机系学生（在student表中）的修课记录（在SC表中）的语句，正确的是（　　）。
单选题 (3 分) 3分
A.
DELETE FROM SC JOIN Student b ON S.Sno = b.Sno


　WHERE Sdept = .计算机系.

B.
DELETE FROM SC FROM SC JOIN Student b ON SC.Sno = b.Sno


　WHERE Sdept = .计算机系.

C.
DELETE FROM Student WHERE Sdept = .计算机系.

D.
DELETE FROM SC WHERE Sdept = .计算机系.