The correct answer is: It was in a good location to be a trading hub.
Explanation: Axum's strategic location at the crossroads of trade routes between Africa, the Mediterranean, and Asia allowed it to thrive as a vital trading center. This position facilitated the exchange of goods, culture, and ideas, which contributed significantly to the city's economic growth and influence. While farming and fishing were also important, the primary factor for Axum's growth was its role in trade.