Given below are the names of four energy crops. Which one of them can be cultivated for ethanol?

Maize (corn) is a starch-rich cereal commonly used as a feedstock for ethanol production; textbooks list maize among crops grown specifically to obtain liquid fuels such as ethanol and alcohol [1], and technical sources identify corn/maize as a primary feedstock for ethanol fermentation in practice [2]. The other options are oil-bearing crops used primarily for oil extraction and biodiesel production: jatropha and sunflower are cited as oilseed crops [3], while pongamia (Pongamia pinnata) is discussed specifically as a biodiesel (non-edible oil) feedstock in biofuel literature [4]. Therefore, maize is the correct choice for cultivation aimed at ethanol production.

Sources

1. [1] Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 12: Major Crops and Cropping Patterns in India > 16. Energy Crops > p. 13
2. [2] https://ntrs.nasa.gov/api/citations/20100002886/downloads/20100002886.pdf
3. [3] Indian Economy, Nitin Singhania .(ed 2nd 2021-22) > Chapter 9: Agriculture > Oil crop > p. 290
4. [4] https://www.scirp.org/journal/paperinformation?paperid=6600