$$ Consider a computer system running a general$-$purpose workload. Measured utilizations $($in terms of time, not space$)$ are

Processor $90\mathrm{.}0\%,$ Disk $5\%,$ Network $20\%.$

For each of the following changes, what is the likely impact on each utilization and why? $($Significant increase, marginally increase, no effect, marginally decrease, or significantly decrease$).$

a$.$ A slower CPU

b$.$ A faster Disk

c$.$ Increase the degree of multiprogramming

d$.$ A faster network