Where must the Cisco UCS bundle image be located before you can begin the upgrade?

You must upgrade a Cisco UCS -Series Server. Where must the Cisco UCS bundle image be located before you can begin the upgrade?
A. the Cisco Integrated Management Controller memory of the server
B. a USB drive connected to a Cisco UCS Fabric Interconnect
C. a TFTP server accessible to the Cisco UCS Fabric Interconnect
D. the flash file system of the fabric interconnect