Question

# Which of the following compounds is an anti-knocking compound?(A) TEL(B) ${{C}_{2}}{{H}_{5}}OH$ (C) Glyoxal(D) Freon

Hint:
An anti-knocking compound is a gasoline additive used to reduce engine knocking and increase the fuel's octane rating by raising the temperature and pressure at which auto-ignition occurs. With this clue in mind, try and match this property with that of the given compounds