Answer : 4. "All of the above"
Explanation :

Answer: D) All of the above Explanation: A computer has two types of memory. 1. Non-volatile and 2. Volatile.   Volatile memory is computer memory that requires power to maintain the stored information. * It is a temporary memeory which cannot contain information permanently. Example :: RAM or Random Access Memory   Non-volatile memory is computer memory that can retain the stored information even when not powered. * It is a permanent memory in which data is stored in permanently. Examples :: Hard disc, ROM, Floppy discs, Magnetic tape,...