Marissa used the set of ordered pairs below to graph a relation.
{(3, 4), (2, 3), (2,0), (4, 2), (3, 6)}
What is the domain of the relations?

{0, 2, 3, 4, 6}

{2, 3, 4}

{0, 2, 3, 4}

{0, 3, 6}