This was not a popular question among the candidates.  Performance was poor.  Most candidates were unable to state the function of the electrostatic discharge (ESD) in a phone workshop. It appears most candidates do not know what ESD is.  Part (b) was poorly handled.
The expected answers are:
                        (a)        ESD prevents the technician from receiving electric shock in the workshop                                     when worn
                        (b)        Any correct 4
                        e.g.      -           The ringer is bad
                                    -           Need to re-align the ringer i.e. bad contact with PCB
                                    -           Phone set to silent mode
                                    -           Phone set to vibration only
                                    -           Phone set to the lowest volume
                                    -           Line bus broken
                                    -           Component(s) serving the ringer is/are bad/disconnected
                                    -           The ringing tone may be empty/corrupt