Cartilage is found in which of the following locations?

Cartilage is a flexible connective tissue that plays various critical roles in the human body. It serves as a cushion between bones in joints, provides support in structures such as the ears, and forms part of the respiratory system. In the given context, the spine and ears are notable locations where cartilage is found.

In the spine, cartilage is specifically present in intervertebral discs, which act as shock absorbers between vertebrae and allow for flexibility and movement. In the ears, cartilage helps maintain shape and support, ensuring that the ear maintains its structure.

Other locations listed, such as knees and lungs, may contain cartilage but are not the primary examples connected with its characteristic functions. The heart and veins do not contain cartilage, as these structures are comprised predominantly of muscle and connective tissues. Similarly, while the brain and kidneys are essential organs, they do not contain cartilage, which primarily serves a supportive or cushioning function in specific areas of the body. Thus, the choice of the spine and ears effectively highlights the key roles of cartilage in maintaining the body's structure and function.