The correct answer is: C. A is true but R is false.
Turpentine oil is a solvent that is commonly used to thin oil-based paints. It is a natural product that is derived from pine trees. Turpentine oil is a clear, colorless liquid with a strong odor. It is flammable and should be used with caution.
Turpentine oil is a good thinner for oil-based paints because it helps to reduce the viscosity of the paint and make it easier to apply. It also helps to improve the flow and leveling of the paint. Turpentine oil can also be used to clean brushes and other painting tools.
However, turpentine oil is not the only type of thinner that can be used for oil-based paints. Other types of thinners, such as mineral spirits and paint thinner, can also be used. These thinners are less expensive than turpentine oil and may be a better option for some people.
The reason given in the question, “Turpentine oil is costlier than other thinners,” is not a correct explanation of the assertion, “Normally turpentine oil is recommended as thinner for indoor painting.” Turpentine oil is a good thinner for oil-based paints, but it is not the only type of thinner that can be used. Other types of thinners, such as mineral spirits and paint thinner, can also be used. These thinners are less expensive than turpentine oil and may be a better option for some people.