Dr. Wong has diagnosed Jim Johnson with a clot in the pericardial space. To remove the clot, a midline sternotomy was performed; the pericardium was incised; and the clot was removed. The procedure recorded on the operative report was pericardiotomy. The appropriate code to report this procedure is ____.​

A)​33015
B)​33020
C)​33030
D)​33025