According to the experiment done by Nilssen et al. (1984), the resting metabolic rate in adult reindeer during winter

A) increases dramatically as the air temperature changes from -40°C to -20°C.
B) decreases significantly as the air temperature changes from 20°C to 40°C.
C) remains about the same as the air temperature changes from 0°C to 10°C.
D) decreases drastically as the air temperature changes from 0°C to 10°C.