单选题

For relation where primary key contains multiple attributes, no non-key attribute should be functionally dependent on a part of primary key. This relation R is at least in (66) .
【正确答案】 A
【答案解析】[解析] 译文：对于主键包含多个属性的关系，没有非主属性函数依赖于部分主键。这样的关系R至少是3NF。