a$)$ i$.$ A computer program wants to load a file from the hard disk into memory. Describe at least three steps that occur during this process.

ii$.$ With the help of a diagram explain the layered architecture of grid computing system.

iii. What are the primary differences between Network Operating Systems and Distributed Operating Systems. State any three.

b$)$ Consider a chain of processes $P_{\text{I}},P_2,$dots,$P_n$ implementing a multitiered client$-$server architecture. Process $P_i$ is client of process $P_{i+1},$ and $P_i$ will return a reply to $P_{i-1}$ only after receiving a reply from $P_{i+l}.$ What are the main problems with this organization when taking a look at the requestreply performance at process $P_l?$