The correct option is D Methyl Tertiary Butyl Ether (MTBE)
MTBE is a gasoline additive, used as an oxygenate to raise the octane number. It is one of a group of chemicals commonly known as oxygenates because they raise the oxygen content of gasoline. It has been used in gasoline at low levels to replace tetraethyl lead and to increase its octane rating to help prevent engine knocking. Oxygenates help gasoline burn more completely, which causes emission of CO2 instead of CO.