A tractor whose weight is 20 tonnes has a drawbar pull of 2500 kg, when operated on a level road having a rolling resistence of 30 kg per tonne. If this tractor is operated on a level road having a rolling resistance of 40 kg per tonne, then the drawbar pull of the tractor will________________?

• A. reduce by 200 kg
• B. increase by 200 kg
• C. increase by 250 kg
• D. reduce by 250 kg