A. The range of the relation is the single value___
B. The range of the relation is the interval_

Use vertical line test to determine whether the graph is the graph of a function.

Look at the y axis. You can see that the graph reaches a minimum at y=3, and then grows indefinitely.

This implies that the range is . In fact, the range is exactly the set of all values reached by the function's outputs.

The vertical line test states that a graph is a function if and only if every possible vertical line crosses the graph at most once.

You can see that this is the case, so this is the graph of a function indeed.