Correct option is C
Internal lapping is used for finishing internal cylindrical surfaces, such as engine cylinder bores. This process uses a soft lap charged with abrasive particles to achieve very high accuracy, smooth surface finish, and precise dimensions.
It is essential in engine components where proper sealing and minimal friction are required. Other types like flat lapping are used for flat surfaces, while belt and chemical lapping are not suitable for cylindrical bores.
Thus, for precision finishing of internal surfaces like cylinder bores.
