I think the best answer for the question your asking is A; the reason why is because with constricted blood vessels and increased blood volume that's your best way to have increased blood pressure.
I would say that the temperate zones though they do have areas such as the Pacific NW that have significant rainfall, but relative to the tropics are apparently relatively dry since they contain most of the world's deserts like the Sahara, the Sonora and the Gobi and the Atacama for example.