B

A radial (longitudinal) split of the diaphragm is preferred because it follows the muscle fibres, avoids circumferential division of the phrenic neurovascular arcade, and heals with minimal loss of contractility, making it the standard approach for most diaphragmatic repairs and plication procedures [Sicular 1992, PMID 1636896; Ito 2020, PMID 32436067].