Environmental friendliness of a vehicle could be measured by the amount of pollutants it emits per passenger per kilometre travelled.Rate the environmental friendliness (1=best & 4=worst) of the following vehicles as per this criterion: Car : scooter : bus : bicycle

The ranking 4:3:2:1 (Car:Scooter:Bus:Bicycle) is correct based on pollutants per passenger per kilometer. Bicycles produce no direct emissions (rank 1, best). Buses carry many passengers, reducing per-person pollution (rank 2). Scooters are more fuel-efficient than cars but carry only 1-2 people (rank 3). Cars carrying 1-4 passengers have the highest per-passenger emissions (rank 4, worst).