Answer:
Option B, thoracotomy
Explanation:
The medical term referring to the general chest area or upper torso is the thorax, and the root phrase denoting this region is thorac/o-.
The suffix that refers to a surgical incision that creates an opening within a region is -otomy.
Combining the two, results in the medical term with a definition that matches the given statement. A thoracotomy is the surgical creation of a new opening in the chest, option B.