Consider a disk queue with I/O requests on the following cylinders in their arriving order: $6,10,12,54,97,73,128,15,44,110,34,45$. The disk head is assumed to be at cylinder $23$ and moving in the direction of decreasing number of cylinders. Total number of cylinders in the disk is $150$. The disk head movement using SCAN –scheduling algorithm is:
- $172$
- $173$
- $227$
- $228$