The answer is C, and the reason why is because the climate changed and since they where not used to that, that affected them, also rainfall and flooding started to shrink and that also contributed to the downfall of the Old Kingdom.
Jamestown offered anchorage and a good defensive position. Warm climate and fertile soil allowed large plantations to prosper.
Plymouth provided good anchorage and an excellent harbor. Cold climate and thin, rocky soil limited farm size. New Englanders turned to lumbering, shipbuilding, fishing and trade.