The statement that correctly analyzes how the cartaz system represented a departure from previous patterns of trade is:
Portuguese ports now had exclusive control of Indian Ocean trade.
The cartaz system, implemented by the Portuguese in the Indian Ocean during the 16th century, required ships to obtain a pass (cartaz) to trade in their controlled waters. This system allowed them to exert significant control over maritime trade routes, which marked a change from previous, more decentralized trading patterns where multiple powers operated with relative autonomy.