A flame contains three parts- black, yellow and blue.

Solution

A flame has three parts basically. A candle flame consists of several different zones with different temperatures. Colors tell us the temperature of the flame. Outer zone Middle zone Inner zone The outermost zone is the hottest among all zones and is blue in color, and this is due to complete combustion. It is the non-luminous part of the flame. The middle zone of the candle flame is moderately hot and is yellow in color, and partial combustion of fuel takes place. It is bright part of the fire. The innermost zone of the flame is the least hot and is black in color. This is due to the presence of unburnt wax vapors. Hence, option B is correct.