Which of the following describes the best reason to defragment magnetic disk drives on a regular basis?

		The time required to sequentially access most files will be limited primarily by the drive's sequential access time rather than its average access time.
		Defragmentation will move all sectors allocated to large files onto a single platter, thus reducing the time required to read those files.
		Longevity of stored data will be greatly extended by rewriting disk sectors at regular intervals.
		Deragmentation will minimize head movement during normal file accesses which will significantly extend the drive's operating lifetime.