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某企业的信息系统管理数据库中的员工关系模式为Emp(员工号,姓名,部门号,岗位,联系地址,薪资),函数依赖集F={员工号→(姓名,部门号,岗位,联系地址),岗位→薪资}。Emp关系的主键为(),函数依赖集F(请作答此空)。
A.存在传递依赖,故关系模式Emp最高达到1NF
B.存在传递依赖,故关系模式Emp最高达到2NF
C.不存在传递依赖,故关系模式Emp最高达到3NF
D.不存在传递依赖,故关系模式Emp最高达到4NF

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