Consider the following sequence of disk track requests: $27,129,110,186,147,41,10,64,120$

Assume the disk bead is initially positioned over track $100$ and is moting in the direction of decreasing track number. Find ou the arerage seek length of the C$.$SCAN disk sctueduling algorithm.

a$.61\mathrm{.}8$

b$.29\mathrm{.}1$

C$.29\mathrm{.}6$

d$.38$