Concept:Volatility is the tendency of a liquid to evaporate readily at a given temperature.
Explanation:A liquid becomes more volatile when it has weaker intermolecular forces and a lower boiling point.
At room temperature, petrol has weak forces between its molecules and a low boiling point.
As a result, petrol evaporates fastest among the given liquids.
Water has strong hydrogen bonding, so it evaporates slowly and is less volatile.
Diesel and kerosine have higher boiling points than petrol, making them less volatile as well.
Hence, petrol shows the highest volatility at room temperature.
Answer:C. petrol