Carter constructs a handmade thermal device to determine what type of material was used to create three cylinders based on their conductive properties. All cylinders are white. Using the properties of temperature and resistance, he is able to calculate the thermal conductivity coefficient (k) for order to determine the material used to create each of the three cylinders. What piece of evidence from the passage supports the conclusion that the handmade thermal device can be used to differentiate among three cylinders? a. recognition that all cylinders are white in color
b. determination that a thermal device could measure conductivity
c. identification of the type of cylinder needed for the study
d. comparison of observed k values to known k values