The correct answer is B. Multiple overwriting.

When storage media will be reused, the goal is to remove sensitive data while keeping the media physically usable. Multiple overwriting writes new patterns of data over existing data so the previous sensitive information is no longer practically recoverable. ISACA describes overwriting as placing an additional layer of information over existing material, with the purpose of protecting the information while not damaging the hard drive itself.

Option A is not correct because cross-cut shredding physically destroys the media. It may be appropriate when media will be disposed of, but not when the storage device must be reused. Option C is not correct because repartitioning changes the disk structure but does not securely erase the underlying data. Option D is not correct because reformatting may remove file system references but often does not securely eliminate recoverable data.

A useful CISA exam point is this:

For reuse, choose logical sanitization such as overwriting.

For disposal, choose physical destruction, degaussing, or shredding depending on the media type and sensitivity.

ISACA notes that common digital data destruction methods include overwriting, degaussing, and physical destruction. Since degaussing and physical destruction generally make media unsuitable for normal reuse, overwriting is the best answer in this question.