Biodiesel is prepared from

Biodiesel is a renewable substitute for petroleum diesel, produced by transesterification of plant or vegetable oils (or animal fats) with an alcohol such as methanol in the presence of a catalyst, yielding fatty acid methyl esters (FAME). For large-scale production that does not compete with food crops, non-edible, oil-rich seed plants that can grow on marginal or waste land are preferred as feedstock.

Jatropha curcas is a hardy shrub whose seeds carry a high, non-edible oil content of about 30-40% by weight. India's National Biodiesel Mission identified Jatropha as the principal feedstock because it thrives on marginal and wasteland without needing prime agricultural land, and its seed oil converts readily to biodiesel through transesterification.

• Utricularia (bladderwort) is a photosynthetic aquatic plant that additionally uses bladder-like traps to capture tiny aquatic organisms, supplementing scarce nutrients such as nitrogen and phosphorus; it is not cultivated as an oil-seed or biodiesel feedstock.

• Cedar is valued as a timber tree and for its aromatic cedarwood oil, used in fragrances and pest-repellent products — a wood and aroma product, not a seed-oil crop.

• Eucalyptus is grown for pulpwood and timber, and its leaves yield a medicinal, aromatic essential oil used in remedies and fragrances — again a wood and aroma product rather than a seed-oil crop.

So, among the given plants, Jatropha's high-oil, non-edible seeds are the one that fit the established biodiesel-feedstock role.