In an experiment, the effect of temperature on the action of amylase is investigated.six different test-tubes are set up,each containing a mixture of amylase and starch solution.which condition should not be kept the same in each of the six test-tubes?

A.concentration of amylase
B.pH
C.temperature
D.volume of starch solution

In an experiment, the effect of temperature on the action of amylase is investigated.six different test-tubes are set up,each containing a mixture of amylase and starch solution.which condition should not be kept the same in each of the six test-tubes?