Consider the following features of newer models of motor cars: I. Radial tyres II. Streamlined body III. Multipoint fuel injection IV. Catalytic converter with exhaust Which of these features make the newer models of motor cars more fuel efficient?

The correct answer is B because Multipoint Fuel Injection and Streamlined Body directly contribute to fuel efficiency. Multipoint Fuel Injection optimizes the air fuel ratio for each cylinder, ensuring complete combustion and reducing fuel wastage. A streamlined body reduces aerodynamic drag or air resistance, allowing the car to move more easily at higher speeds with less fuel consumption.

While radial tyres offer better grip and catalytic converters reduce harmful emissions, they are primarily safety and environmental features rather than primary drivers of fuel efficiency in this context. Specifically, catalytic converters can sometimes slightly decrease fuel economy due to exhaust backpressure. Therefore, features II and III are the most accurate choices for improving fuel efficiency.