Look at this set of ordered pairs.

{ (4, 12), (7, 11), (3, 13), (11, 4), (7, 3)}

which statement about the relation above is true?

it is not a function because every y-value has more than one x-value.

it is not a function because the same values appear as both x and y-values.

it is a function because every x-value is unique.

it is a function because every x-value has only y-value.