Consider the Raft consensus system. Suppose you have a five-server Raft system. Here's the state of the servers' logs: 

S1: 3.1 4.1
S2: 3.1 3.2
S3: 3.1 5.1
S4: 3.1 5.1 5.2
S5: 3.1

The notation T.N means the Nth log entry from term T. The servers are about to choose a new leader.

Please answer the following questions:

(a) Could any replica have already executed the operation in log entry 5.1? If yes, how? If no, why?

(b) Could operation 3.2 be committed in the future? If yes, how? If no, why?

(c) Could operation 4.1 be committed in the future? If yes, how? If no, why?