Main bus and transfer bus- In this arrangement one or more busses is added to the single bus substation scheme. One or more circuit breakers may be used in this arrangement to make connection between the main and transfer bus in the main and transfer bus configuration, the protective relay scheme is quite complex due to the requirement of the tie breaker to handle each situation for maintenance of any other circuit breaker. This bus scheme is more costly than the single bus configuration but is more reliable and can be easily expanded.

Hence, the correct option is (C).