If f={(4,2),(5,1),(6,2),(7,3),(8,6)} then the range of f is what

If f={(4,2),(5,1),(6,2),(7,3),(8,6)} then the range of f is what

The range is the full set of all possible y-values:
{1, 2, 2, 3, 6}

Remove duplicates, we get:
{1, 2, 3, 6}