从关系规范化理论的角度讲，一个只满足1NF的关系可能存在的四方面问题是：数据冗余度大、修改异常、插入异常和______。

A．SELECT sno FROM sc WHERE sname=′王′
B．SELECT sno FROM sc WHERE sname IS LIKE′王%′
C．SELECT sno FROM sc WHERE sname LIKE′王%′
D．SELECT sno FROM sc WHERE sname LIKE′王_′