Refer to the exhibit.HostA cannot ping HostB.Assuming routing is properly configured,what could be the cause of this problem?（）

• A、HostA is not on the same subnet as its default gateway
• B、The address of SwitchA is a subnet address
• C、The Fa0/0 interface on RouterA is on a subnet that cannot be used
• D、The serial interfaces of the routers are not on the same subnet
• E、The Fa0/0 interface on RouterB is using a broadcast address