You will conduct an experiment of your own design to investigate thermoregulation in crickets. Which of the following factors would be the most important independent variable (experimentally controlled / varied / manipulated by you) to determine the relationship of temperature and metabolism rate in crickets?
a) -sex of cricket
b) -time
c) -variation in cricket body temperature
d) -variation in ambient / surrounding environment temperature
e) -cricket response (change in metabolic rate)