Directions: Carry One Mark Each.

An electric bus has on-board instruments that report the total electricity consumed since the start of the trip as well as the total distance covered. During a single day of operation, the bus travels on stretches M, N, O and P, in that order. The cumulative distance travelled and the corresponding electricity consumption are shown in the table below. Stretch| Cumulative distance (km)| Electricity used (kWh) | | M| 20|12| | N| 45| 25| | O| 75| 45| | P| 100| 57|

Which of the following is the stretch where the electricity consumption per km is the minimum?