The correct answer is C. Core memory.
Core memory is a type of computer memory that uses small ferrite rings to store data. The rings are arranged in a matrix, and each ring can be magnetized in one of two directions to represent a 0 or a 1. Core memory was the most common type of memory used in computers from the 1950s to the 1970s.
ROM (read-only memory) is a type of memory that can be read but not written to. ROM is used to store firmware, which is the software that controls the basic functions of a computer.
Magnetic disk is a type of storage device that uses a magnetic field to store data. Magnetic disks are commonly used to store data in computers and other electronic devices.
Bubble memory is a type of non-volatile memory that uses magnetic bubbles to store data. Bubble memory was once a promising technology for computer memory, but it was eventually replaced by other technologies such as flash memory.
E. None of the above is not the correct answer.