Which of the following shows the union of the sets?

{4, 8, 12, 16, 20, 24, 28} {2, 4, 6, 8, 10, 12}
{4, 8, 12}
{4, 8, 12, 16}
{6, 8, 10, 12}
{2, 4, 6, 8, 10, 12, 16, 20, 24, 28}