Refer to the exhibit.  Which Virtual Router Redundancy Protocol （VRRP） statement is true about  the roles of the master virtual router and the backup virtual router？（）

• A、 Router A is the master virtual router， and Router B is the backup virtual router. When Router A  fails， Router B will become the master virtual router. When Router A recovers， Router B will  maintain the role of master virtual router.
• B、 Router B is the master virtual router， and Router A is the backup virtual router. When Router B  fails， Router A will become the master virtual router. When Router B recovers， it will regain the  master virtual router role.
• C、 Router A is the master virtual router， and Router B is the backup virtual router. When Router A  fails， Router B will become the master virtual router. When Router A recovers， it will regain the  master virtual router role.
• D、 Router B is the master virtual router， and Router A is the backup virtual router. When Router B  fails， Router A will become the master virtual router. When Router B recovers， Router A will  maintain the role of master virtual router.