Before ignition, oil must be what?

The correct choice is that oil must be atomized before ignition. Atomization refers to the process of breaking the oil into tiny particles or droplets. This transformation is necessary because, in combustion systems, the oil needs to mix thoroughly with air to facilitate efficient burning. When oil is atomized, it increases the surface area available for combustion, leading to a more complete and efficient ignition process.

Heating oil may help improve its flow and reduce viscosity, but it does not ensure that the oil is in the ideal state for combustion. Similarly, while vaporization can occur in certain heating methods, atomization is the specific requirement for efficient ignition in typical oil-burning appliances. Aeration, which involves mixing air with the oil, does not achieve the same goal of creating a fine mist suitable for combustion. Therefore, atomization stands out as the crucial step needed to achieve optimal combustion efficiency.