Which one of the following is an eco-friendly solvent ?

Water is considered the most eco-friendly solvent among the given options. In the framework of Green Chemistry, selecting safer solvents is a key principle to minimize environmental and health risks. Water is non-toxic, non-flammable, biodegradable, and does not contribute to Volatile Organic Compound (VOC) emissions.

• Benzene is a potent carcinogen and a hazardous air pollutant.
• Carbon disulphide is highly volatile, toxic to the central nervous system, and poses significant fire hazards.
• Liquid ammonia is a pungent, corrosive gas at room temperature; its use as a solvent requires high pressure or cryogenic cooling and poses toxicity risks.

Due to its safety profile and lack of environmental toxicity, water is the primary choice for sustainable chemical synthesis.