Answer Description
Don't let the wording confuse you! You are looking for the option that is NOT described as non-volatile. Non-volatile memory retains data without a power source. Flash memory (like in thumb drives), SSD hard drives and tape drives do not require a power source to retain data. Random Access Memory (RAM) is volatile and loses its data without a power source and is therefore not described as non-volatile.
Wikipedia
Non-volatile memory (NVM) or non-volatile storage is a type of computer memory that can retrieve stored information even after having been power cycled. In contrast, volatile memory needs constant power in order to retain data. Examples of non-volatile memory include flash memory, read-only memory (ROM), ferroelectric RAM, most types of magnetic computer storage devices (e.g. hard disk drives, floppy disks, and magnetic tape), optical discs, and early computer storage methods such as paper tape and …
Non-volatile memory - Wikipedia, the free encyclopedia