7. Consider a hard drive of moving-head mechanism. Given that the current head position is at cylinder 119, the disk arm is moving toward 0, and disk read requests on cylinders 88, 168, 37, 117, 14, 124, 65, and 67 are pending. Moreover, a new request at cylinder 99 interrupts right before the 3rd reading finishes and the requests in queue are then rescheduled with this new request. Determine the sequence of cylinders the head visits for the following disk-scheduling algorithms: (a) SSTF (4%) (b) SCAN (4%) (c) C-LOOK (4%) x