The correct answer is C. Formation of lather with soap.
Hard water
is water that contains high levels of minerals, such as calcium and magnesium. These minerals can interfere with the formation of lather when soap is added to water. The more minerals in the water, the more difficult it is to form lather.To test the hardness of water, you can add a small amount of soap to a glass of water. If the water is hard, you will not be able to form a lot of lather. If the water is soft, you will be able to form a lot of lather.
Boiling and distillation do not affect the hardness of water. Boiling water will only remove dissolved gases from the water, not minerals. Distillation will remove all of the dissolved minerals from the water, but it will also remove all of the other dissolved substances, such as salts and nutrients.
Therefore, the correct answer is C. Formation of lather with soap.