Which cue best supports ribcage stability during arm work on the reformer?

• A. Keep shoulders square and ribs relaxed.
• B. Breathe diaphragmatically using belly breathing.
• C. Tense the obliques to keep ribs down.
• D. Keep ribs connected to the pelvis, prevent rib flare, lengthen the sternum, and breathe laterally to maintain trunk stability.

Answer: (D)