Which is a criterion for a good fuel?

1. A fuel is judged on how well it delivers energy once burnt. 2. A good fuel supplies energy continuously and at a high rate. 3. It should also have a high calorific value, meaning high energy released per unit mass. 4. Carbon dioxide is the main product of combustion rather than a quality of the fuel, and it pollutes the environment. 5. Non-combustible material should be low, not high, since it does not burn and leaves ash behind. _Source: NECTA CSEE 2022 Chemistry 032, Question 1: Multiple Choice Items, item (iii)_