The correct answer is C.
The Greek colonization period took place between the 6th and 8th centuries BC, in the Mediterranean Sea and Black Sea regions. This demographic process was centrally desgined, and the metropolis made the decisions about how it should be conducted. Many of the Greek settlements became strong cities afterwards.
The main reason that triggered this colonisation, was the demographic explosion that had taken place and the scarcity of farms and their production which could not cope with the population expansion in some regions, and this caused the desire of finding new regions to establish themselves. The decision of establishing a colony in a certain location depended on its potential, first of all, the kind of raw materials that could be taken to the metropolis and also the type of final goods that could be produced afterwards. Colonies were a big source of wealth for the Greeks.