Answer: Option (d) is the correct answer.
Explanation:
A mixture in which solute particles are unevenly distributed into the solvent then it is known as a heterogeneous mixture.
For example, salad is a heterogeneous mixture.
Components of a mixture never combine chemically with each other.
A homogeneous mixture is defined as the mixture in which solute particles are evenly distributed in a solvent.
A homogeneous mixture is a clear solution.
For example, salt dissolved in water is a homogeneous mixture.
Sodium chloride is a chemical compound and not a mixture. Whereas oxygen is an element and not a mixture.
Thus, we can conclude that out of the given options salt water is a homogeneous mixture.