Answer Description

The answer is degaussing. Degaussing is the method of physical media destruction that exposes the drive to a very high magnetic field using a machine called a degausser. This erases all data on the hard drive and renders it unusable. Formatting is only a way to delete the data on the hard drive, while the other choices are all ways to physically render the drive unusable but not delete data.

Wikipedia

Degaussing is the process of decreasing or eliminating a remnant magnetic field. It is named after the gauss, a unit of magnetism, which in turn was named after Carl Friedrich Gauss. Due to magnetic hysteresis, it is generally not possible to reduce a magnetic field completely to zero, so degaussing typically induces a very small "known" field referred to as bias. Degaussing was originally applied to reduce ships' magnetic signatures during World War II. Degaussing is also used to reduce magnetic fields in cathode ray tube monitors and to destroy data held on magnetic storage.