A student performed a laboratory investigation to
determine the effect of temperature on the heart rate of Daphnia (water flea). The following temperatures and
heart rates were recorded:
20° C-260 beats/min;
10° C-152 beats/min;
25° C-300 beats/min; 5°C-108 beats/min;
15°C-200 beats/min

During which temperature interval did the greatest change in heart rate occur?

a) 5-10 °C
b) 15-20 °C
c) 10-15 °C
d) 20-25 °C