5 climate types are: Hot, really hot, cold, freezing, and in between. One example of really hot is the desert, it is always hot there and sandy, it almost never rains so it is perfect for the lizards and other animals that live there. Cold is like a tundra, it is usually always cold, freezing is the arctic, where polar bears etc live. In between is like a meadow or field.
A or C
Just choose any of those!
Graphs that are clearly labeled are much less likely to be misread or misinterpreted.
Studies of populations that reveal correlations between dietary habits and disease incidence are epidemiological studies.