Which term specifically refers to a bronchiole?

The term that specifically refers to a bronchiole is actually represented by combining forms related to bronchi. The correct term for bronchiole is derived from "bronch/i" which denotes the smaller branches of the bronchial tubes. The suffix -ole indicates a small or diminutive form.

In the given options, "bronch/o" (which refers to the bronchus) is the more general term for the larger air passages leading from the trachea to the lungs. The term "bronchi/o" is also related but does not specifically denote the smaller, fine branches called bronchioles. The choice "brachi/o" refers to the arm and is unrelated to the respiratory system, while "calc/o" relates to calcium and is also not connected to the respiratory anatomy.

Thus, the correct answer demonstrates an understanding of the terminology used to describe the lower structures of the respiratory system, specifically focusing on the distinction between bronchi and bronchioles.