In the deepest intercostal muscle layer:

• A. the subcostals line the rib cage at the side
• B. fibres of the innermost intercostal group only span one intercostal space
• C. fibres of the subcostals group only span one intercostal space
• D. transversus thoracis fibres only arise from 2nd to 6th costal cartilages
• E. the border of the subcostal muscle group meets the innermost intercostal groups, overlapping slightly so the intercostal artery can slip between them to join the intercostal nerve