RC-2, MC-2 and SC-2 correspond to A. same viscosity B. viscosity in increasing order from RC-2 to SC-2 C. viscosity in decreasing order from RC-2 to SC-2 D. none of the above

The correct answer is: A. same viscosity

RC-2, MC-2, and SC-2 are all grades of motor oil. The viscosity of a fluid is a measure of its resistance to flow. The higher the viscosity, the more resistant the fluid is to flow. Motor oil is graded according to its viscosity, with the higher the grade, the thicker the oil. RC-2, MC-2, and SC-2 are all low-viscosity oils, which means they are thin and flow easily. This makes them ideal for use in cold weather, when the oil needs to flow easily to lubricate the engine.

Option B is incorrect because the viscosity of RC-2, MC-2, and SC-2 is not in increasing order from RC-2 to SC-2. The viscosity of RC-2 is the same as the viscosity of MC-2, which is the same as the viscosity of SC-2.

Option C is incorrect because the viscosity of RC-2, MC-2, and SC-2 is not in decreasing order from RC-2 to SC-2. The viscosity of RC-2 is the same as the viscosity of MC-2, which is the same as the viscosity of SC-2.

Option D is incorrect because RC-2, MC-2, and SC-2 do correspond to the same viscosity.