A jet aeroplane is flying long range cruise. How does the specific range / fuel flow change?

So you would assume that as you are flying, the aircraft mass goes decreasing.
(Mass at T0 > Mass at T1).

Therefore, as the Specific Range is given by "Distance/Fuel" we can say that at T0 the distance you can cover per unit of fuel is less than the distance you can cover per unit of fuel at T1.

So, Flying LRC (or flying whatever) the Specific Range INCREASES along the flight

Now as the a/c is lighter along the flight, to maintain a given speed, the Fuel Flow DECREASES

So INCREASES / DECREASES would be the correct answer