Please help

Jonathan is trying to drain his pool to install a new liner. The graph below represents the amount of water remaining in his pool as he drains it.

A)

Number of Gallons drained per hour; Number of hours (Independent Variables)

Number of Gallons in the pool (Dependent Variable)

B) -25 (It's the negative value of how many gallons are drained in an hour)

C)13000 (It means how many gallons were in the pool to begin with)

D)3000 (It's the corresponding value for 40 as the x-value)

i would say true? if the unit was informational and it "refreshed your understanding", then true.