Superiorly, a ___ ___ is defined by drawing an imaginary line across the inferior borders of the ___ ___ ___. This plane is called the ___ ___. a) Transthoracic plane; rib cage; thoracic plane b) Transverse plane; rib cage; subcostal plane c) Sagittal plane; sternum; costal plane d) Coronal plane; rib cage; subcostal plane