Students set up a controlled experiment. they put up five crickets in each of three identical containers. they set one container to 15 degrees Celsius one to 20 degrees Celsius and one to 25 degrees Celsius then they count the number of chirps in each container during 1 hour what is the manipulated variable in this experiment
a. the kind of container used
b. the temperature of each container
c. the number of cricket chirps
d. the number of crickets in each container