What is the domain and range of the relation represented by the set of ordered pairs? {(2, 6), (2, 0), (-4, -2), (-4, 6)}

A:
The mapping does not represent a relation.

B:
D: {0, 2, 6}
R: {-4, -2}

C:
D: {-2, 2, 6}
R: {-4, 0, 2}

D:
D: {-4, 2}
R: {-2, 2, 6}