None of these cables will plug into the 3548, which has 48 copper RJ45 ports and two uplink Gbps ports for transceivers.  You will need to use the copper ethernet RJ45 ports or one/both of the two SFP ports. The SFP ports are fiber transceivers designated as 10000 Base-SX or LX.  The bottom picture is an SFP SC and to connect this one to an SFP LC in the switch, you will need an LC to SC cable and an LC transceiver.  The first two pictures are a bit blurry, but in order for either of them to work with the 3548, you will need the LC tranceiver and the cable to join the two. The 3548 supports SR, LR, and LRM tranceivers available at Dell. -Victor
i'm planning to install 3 x Powerconnect 3548's onto my network and need to know which modules to use for these 3 x specific cablings we have: can you help in specifying please?  Cable A [IMAGE]  Cable B [IMAGE]  Cable C [IMAGE]              
Powerconnect 3548's, need advice please re: cable connection modules