ANS:B - radiation

In a furnace where the heating element temperature is at 1700°C, radiation is the dominant mechanism of heat transfer. Radiation is the transfer of heat energy in the form of electromagnetic waves, and it occurs between surfaces that are at different temperatures. In high-temperature environments such as furnaces, where there may not be direct contact between the heating element and the object being heated, radiation is the primary mode of heat transfer. Conduction and convection are less significant compared to radiation at such high temperatures.