Give a chemical test to distinguish between saturated and unsaturated hydrocarbons.

Unsaturated hydrocarbons are those in which either a double bond or a triple bond is present, whereas saturated hydrocarbons are those in which all of the bonds are single bonds. The bromine water test is one of the most effective methods for identifying them.

One of the important tests that can be used for distinguishing saturated and unsaturated hydrocarbons is the bromine water test.

When bromine water is treated with an unsaturated hydrocarbon,  it has been found that the color of the solution will change from red-brown to colorless. 

But when this bromine solution is treated with saturated hydrocarbon, it has been found that the color of the solution remains the same.

Therefore we can say that unsaturated hydrocarbon can decolorize the bromine water whereas saturated hydrocarbon cannot.

Hence option B is correct.