Endothermic animals respond to the drop in environmental temperatures by increasing metabolic rates. The heat lost to the environment is compensated by the heat energy generated by metabolism. The speed of heat loss is proportional to the ratio of surface area to body weight. Researchers are using weasels and woodrats, two small-sized mammal species, to study the relationship between metabolic rate and environmental temperature. It is known that for the same body weight, a weasel has a larger surface area than woodrats. In this experiment, a weasel and a woodrat of the same body weight were exposed to temperatures between 0 and 20 Celsius, respectively. The metabolic rate was then measured at each temperature and plotted against environmental temperatures.

Which graph represents the result expected from this experiment? EDGE 2021