From the data, they concluded that bubble wrap was the best insulating material. what is the weakness in the conclusion? a) it is the better of two insulators only; it is not the best insulator. b) the experiment should have been continued till the temperatures of the cans reached 0°c. c) the experiment must be repeated at least three times before this conclusion can be drawn. d) the data on the can without insulator is irrelevant and distracts from the main idea of the experiment.