Answer:
D. 2 ≤ x ≤ 5
Explanation:
Notice that there are no points on the graph for x ≤ 2 and x ≥ 5. Or another way to look at it is that the x's are between 2 and 5, inclusive.
The domain is the set of possible x values. Therefore, 2 ≤ x ≤ 5 is the set of values for the domain