删除计算机系学生(在student表中)的修课记录(在sc表中)的正确的SQL语句是_____。
A.
delete from sc join student b on sc.sno=b.sno where sdept = '计算机系'
B.
delete from sc where sno in (select sno from student where sdept = '计算机系')
C.
delete from sc where sno = (select sno from student where sdept = '计算机系')
D.
delete from sc where sdept = '计算机系'