Latex of some plants containing long-chain hydrocarbons is considered to be a good substitute for liquid fuels or petroleum. Such plants having large amount of latex with long chain hydrocarbon are called petroplants. Cultivation of petroleum is also a part of energy cropping. cultivation of this petrocrop was first of all done by Italians in Ethiopia about fifty year back. Although actual credit for identifying the petrocrop crops goes to Dr. Calvin. The most common petroplants belongs to family Euphorbiaceae, Asclepiadaceae, Apocynaceae, Compositae, Labiatae, Sapotaceae, urticaceae etc. which have property of converting large amount of their photosynthesis into latex with hydrocarbons. Their hydrocarbons contents can be increased by genetic manipulations.
So, the correct option is 'Euphorbiaceae'.