如果学生表STUDENT是使用下面的SQL语句创建的CREATE TABLE STUDENT (SNO C (4) PRIMARY KEY NOT NULL , SN C (8) , SEX C (2) , AGE N (2) CHECK (AGE>15 AND AGE<30 ))下面的SQL语句中可以正确执行的是A)INSERT INTO STUDENT(SNO,SEX,AGE)VALUES('S9','男',17)B)INSERT INTO STUDENT(SN,SEX,AGE)VALUES('','男',20)C)INSERT INTO STUDENT(SEX,AGE)VALUES('男',20)D)INSERT INTO STUDENT(SNO,SN) VALUES('S9','',16)