nMOS fabrication process is carried out in . . . . . . . . A. Thin wafer of a single crystal B. Thin wafer of multiple crystals C. Thick wafer of a single crystal D. Thick wafer of multiple crystals

The correct answer is: A. Thin wafer of a single crystal.

A thin wafer of a single crystal is used in the nMOS fabrication process because it allows for the creation of very small, precise structures. The wafer is made of a semiconductor material, such as silicon, and is then etched and doped to create the desired electronic components.

A thin wafer of multiple crystals would not be as suitable for the nMOS fabrication process because it would be more difficult to create the precise structures that are necessary. Additionally, the multiple crystals would create defects in the semiconductor material, which could affect the performance of the electronic components.

A thick wafer of a single crystal would also not be as suitable for the nMOS fabrication process because it would be more difficult to etch and dope the material. Additionally, the thick wafer would be more likely to break during the fabrication process.

Therefore, the correct answer is: A. Thin wafer of a single crystal.