Which combining form is associated with the chest?

The combining form that relates to the chest is "thorac/o." This term comes from "thorax," which is the part of the body between the neck and the abdomen. In the context of veterinary medicine, physicians and veterinary professionals often use this combining form to describe conditions, procedures, or anatomical structures associated with the thoracic cavity, such as thoracotomy (surgical opening of the thorax) or thoracic ultrasound.

The other choices refer to different anatomical regions or functions. "Cardi/o" pertains to the heart, "dent/o" refers to teeth, and "pneum/o" is associated with the lungs or air. Each combining form is specific to its context and area of the body, which helps to precisely convey medical information.