When giving chest compressions during CPR the thoracic cavity can flex in and out without breaking bones. What is one reason that the thoracic cage is able to flex in this manner?

• A. Flexible costal cartilage comprises a large portion of the anterior thoracic cage.
• B. Ribs have a curved shape allowing them to flex and bend easily.
• C. The floating ribs have no connection to the sternum allowing the thoracic cage to change shape easily.
• D. The sternum is made of three bones that can easily bend where they form joints with each other.