how to get the only ethernet macc address using C#.net

public string GetMACAddress()
       {
           ManagementClass mc = new ManagementClass("Win32_NetworkAdapterConfiguration");
           ManagementObjectCollection moc = mc.GetInstances();
           string MACAddress = String.Empty;
           foreach (ManagementObject mo in moc)
           {
               if (MACAddress == String.Empty) // only return MAC Address from first card
               {
                   if ((bool)mo["IPEnabled"] == true) MACAddress = mo["MacAddress"].ToString();
               }
               mo.Dispose();
           }
           MACAddress = MACAddress.Replace(":", "");
           return MACAddress;

       }