The correct answer is C. Put data into secondary storage.
A save operation is a process of storing data on a secondary storage device, such as a hard drive, USB drive, or optical disc. This data can then be retrieved later, even if the computer is turned off.
Option A is incorrect because the processor is the part of the computer that executes instructions. It does not store data.
Option B is incorrect because internal memory is a temporary storage location for data. It is erased when the computer is turned off.
Option D is incorrect because the monitor is a display device. It does not store data.