The correct answer is: B. Magnetic tape
Magnetic tape is a sequential access storage device, which means that data is stored in a linear fashion and can only be accessed in order. This is in contrast to random access storage devices, such as RAM and hard drives, which can access data at any point in the storage medium.
Magnetic tape is often used for backup and archiving purposes, as it is a relatively inexpensive and reliable way to store large amounts of data. It is also used in some data processing applications, such as batch processing.
RAM (random access memory) is a volatile memory device, which means that it loses its contents when the power is turned off. RAM is used to store data that is currently being used by the computer, such as the operating system, programs, and open files.
Hard drives are non-volatile storage devices, which means that they retain their contents even when the power is turned off. Hard drives are used to store data that needs to be accessed frequently, such as documents, photos, and music.
Core memory is a type of magnetic storage device that was used in early computers. Core memory is no longer used in modern computers, as it has been replaced by more efficient storage technologies, such as RAM and hard drives.