The correct answer is A. White lime.
White lime is a type of lime that is produced by heating limestone to a high temperature. It is a white powder that is used in a variety of applications, including white washing. White washing is a process of applying a thin layer of lime to a surface to create a white, opaque finish. It is often used to whitewash exterior walls of buildings, but it can also be used on interior walls and ceilings.
Fat lime is a type of lime that is produced by heating limestone to a lower temperature than white lime. It is a cream-colored powder that is used in a variety of applications, including mortar, plaster, and concrete.
Hydraulic lime is a type of lime that is produced by heating limestone to a high temperature in the presence of water. It is a grayish-white powder that is used in a variety of applications, including mortar, plaster, and concrete.
Quick lime is a type of lime that is produced by heating limestone to a very high temperature. It is a white powder that is used in a variety of applications, including making cement, plaster, and whitewash.
White lime is the most commonly used lime in white washing because it is the most effective at creating a white, opaque finish. It is also the least expensive type of lime.