I think is iron and machinery.?
Greece is very hilly so it was hard for the ancients greeks to farm the land and use crops as a main source of food so instead they use sea food as a main source of food since they are sorounded by the ocean.
The answer is A, the rest don’t really seem reasonable. And during the middle ages it was a time for great process in arts and SCIENCE! And the only one involving science is A :))
