Which two factors the greek city-states develop strong economies? trade the mountainous terrain colonization war

Momentarily war always gives a kick start to an economy. But not always. The problem the United States is having right now is not winning the war. It is winning the occupation in Iraq and Afghanistan.
A mountainous terrain would be a hindrance to trade. 

I would pick trade and colonization. They did do some of that. A third answer is that they developed things to sell.