Answer:
Option D, Water
Step-by-step explanation:
A compound is a basically composed of two or more different elements. Of all the given options, Sodium is an individual element. Hence it is not a compound. Just like sodium, chlorine and Nitrogen are also individual elements. Therefore, both chlorine and nitrogen are also not compound but water is composed of two different elements - a) Oxygen and b) Hydrogen.
Mixture of oxygen and hydrogen in the ratio of 1:2 respectively under suitable conditions produces water which is a mixture of more than one element.
Hence, Water is a compound.
Option D is correct