Glycol is added to aviation gasoline because it A. Reduces evaporation of petrol B. Increases efficiency of petrol C. Prevents freezing of petrol D. Reduces consumption of petrol

The correct answer is C. Glycol is added to aviation gasoline to prevent freezing of petrol.

Glycol is a type of alcohol that is used as an antifreeze. It lowers the freezing point of water, which prevents the petrol from freezing in cold weather. This is important for aviation gasoline, as it is often used in cold climates.

The other options are incorrect. Option A is incorrect because glycol does not reduce evaporation of petrol. Option B is incorrect because glycol does not increase efficiency of petrol. Option D is incorrect because glycol does not reduce consumption of petrol.