Which of the following is a true solution ?A) NaCl in sulphur dioxideB) Copper in silverC) Salt in petrolD) Mud in water

A solution is a homogeneous mixture of two or more substances. The substance in the smallest amount and the one that dissolves in the other substance is called the solute. The substance in the larger amount is called the solvent.

Let's analyze each option:

A) NaCl in sulphur dioxide: Sodium chloride (NaCl) does not dissolve in sulphur dioxide, so this is not a solution.

B) Copper in silver: Copper does not dissolve in silver. They can form an alloy, which is a solid mixture, but not a solution.

C) Salt in petrol: Salt does not dissolve in petrol. Petrol is a nonpolar solvent, while salt is an ionic compound, and "like dissolves like". This means that polar substances dissolve in polar solvents, and nonpolar substances dissolve in nonpolar solvents. So, this is not a solution.

D) Mud in water: Mud does not dissolve in water. It forms a heterogeneous mixture, not a solution.

So, none of the options given is a true solution.