Ramil G. answered 16d
The method that is NOT used at Great Zimbabwe to emphasize the social boundary between nobles and commoners is "Painted large victorious battle scenes on the walls of rulers' tombs." While Great Zimbabwe did feature intricate stone walls, limited commoners' access to ceremonial activities, and maintained exclusive access to long-distance trade networks in prestige items, there is no evidence of large victorious battle scenes being painted on the walls of rulers' tombs as a means to emphasize social boundaries. The other methods mentioned were indeed employed to highlight the distinction between nobles and commoners at Great Zimbabwe.