A scientist performed an experiment to learn how the thickness of a piece of wood affects its ability to support weight without breaking. The scientist prepared three different pieces of wood and applied weight until they broke. The results are shown in the table below. Thickness of Wood Breaking Weight 1 cm 15 kg 2 cm 29 kg 3 cm 42 kg Which variable is intentionally controlled by the experimenter? A. The type of scale used to measure the weight O B. The thickness of the wood O C. The breaking weight D. The number of pieces of wood