In the context of alternative sources of energy, ethanol as a viable bio-fuel can be obtained from:

Sugarcane is the most direct and widely used feedstock for bioethanol: sugarcane juice is processed to molasses which is fermented to produce ethanol, and several countries use alcohol from sugarcane as a petrol additive [1]. First‑generation ethanol production commonly relies on sucrose from sugarcane and sugar beet, while starch‑based crops (e.g., wheat, corn, potato) must first be hydrolysed to release fermentable sugars (glucose) before fermentation and distillation [2]. Among the four options given, sugarcane is the classical and most efficient source for ethanol production, making option 3 the best single choice.

Sources

1. [1] Science , class X (NCERT 2025 ed.) > Chapter 4: Carbon and its Compounds > Alcohol as a fuel > p. 73
2. [2] https://www.sciencedirect.com/topics/engineering/bioethanol-production