A retail customer installs a BladeCenter into an existing 10/100 Ethernet network. Due to cost considerations， the customer uses Copper Pass-thru Modules. After installing this solution， the customer finds that they have no network connectivity. Which is causing the problem of the following？（）

A.Copper Pass-thru Modules only support 1000Mb line speeds.
B.Spanning Tree has been enabled on the Copper Pass-thru Module.
C.The customer does not have the latest firmware loaded on the Copper Pass-thru Module.
D.The customer is using LS21 Blades