For combustion reaction to take place there should beoxygenflamefuelall of the above

All of the above. For a combustion reaction to occur, there needs to be oxygen, flame (heat source), and fuel. These three elements are often referred to as the "fire triangle," and all are necessary for combustion to take place.

1. Oxygen: Combustion reactions are oxidation reactions, meaning they require oxygen to occur. In most cases, this oxygen comes from the air.

2. Flame (Heat): Heat is needed to start the reaction and keep it going. This is usually provided by a flame, but other heat sources can also be used.

3. Fuel: This is the substance that is being oxidized or burned in the reaction. It could be a variety of substances, including wood, gasoline, or natural gas.

So, the correct answer is "all of the above."