How do hybrid school buses improve fuel efficiency?

Answer: C — By using both diesel and electric power

Hybrid school buses improve fuel efficiency by utilizing both diesel and electric power. This dual-source energy system allows the bus to take advantage of the strengths of each power type. When operating at lower speeds, such as during stop-and-go traffic or when idling, the electric motor can be used, which is more efficient than a diesel engine in those conditions. Conversely, when more power is needed, such as during acceleration or traveling at high speeds, the diesel engine can engage. This combination not only enhances fuel economy but also reduces emissions, making hybrid buses a more environmentally friendly option compared to traditional diesel-only buses. The other options do not capture the essence of how hybrid systems work. Relying solely on electric power would not provide the range and power under all driving conditions typically needed for a school bus. A larger fuel tank does not inherently enhance efficiency; it simply allows for a longer range before refueling without changing the consumption rate. Reducing passenger capacity would affect the bus's functionality and does not contribute to fuel efficiency improvements.