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 retain stored information even after power is removed. In contrast, volatile memory needs constant power in order to retain data. Non-volatile memory typically refers to storage in semiconductor memory chips, which store data in floating-gate memory cells consisting of floating-gate MOSFETs (metal–oxide–semiconductor field-effect transistors), including flash memory storage such as NAND flash and solid-state drives (SSD). Other examples of non-volatile memory include read-only memory (ROM), EPROM (erasable programmable ROM) and EEPROM (electrically erasable programmable ROM), ferroelectric RAM, most types of computer data storage devices (e.g. disk storage, hard disk drives, optical discs, floppy disks, and magnetic tape), and early computer storage methods such as punched tape and cards.