Answer:
B
Step-by-step explanation:
The y-axis shows the number of gallons of water left (with respect to time).
The x-axis shows the time.
Domain is the set of x-values that is allowed. Looking at the graph, we see that the water drains within 0 to 12 minutes. After 12 minutes there is no water left, so that's not feasible. Hence, the domain would be from 0 to 12.
Looking at the choices, that is B, 0 ≤ x ≤ 12