Final answer:
Radiation is the dominant heat-transfer method in broiling due to the high-temperature gradient created by the gas flame or electric heating element.
Step-by-step explanation:
Radiation is the dominant heat-transfer method in broiling. This is because a gas flame or electric heating element produces a very high temperature close to the food and above it, creating a high-temperature gradient. Radiation transfers heat energy through electromagnetic waves, allowing the high temperature to be directly applied to the food, resulting in faster and more intense cooking.