Use the list$-$processing algorithm to schedule the tasks in the following orderrequirement digraph on

a$.$ Two Processors using the list $T1,T2,T3,T4,T5,T6,T7$

b$.$ Two Processors using the list $T1,T2,T3,T4,T6,T5,T7$

c$.$ Will adding a third processor enable the tasks to be finished earlier?

d$.$ Which tasks in this order$-$requirement digraph can be shortened and not affect the completion time of all the tasks?