Which of the following conditions will make a relation that is in first normal form. to be in second normal form?

Ⅰ.every non-key attribute is functionally dependent on the full set of primary key attributes.

Ⅱ.no non-key attributes exist in the relation.

Ⅲ.the primary key consists of only one attribute.

A．Ⅰ only

B．Ⅰ and Ⅱ only

C．Ⅰ and Ⅲ only

D．any of them