Cartilage grows in two ways, appositional and interstitial. what is appositional growth? a. along the edges only of existing osteons, making each osteon larger b. the secretion of new matrix against the external face of existing cartilage c. the lengthening of hyaline cartilage d. growth at the epiphyseal plate

The main difference between appositional and interstitial growth is where it occurs and what happens when it occurs. For interstitial growth it occurs inside the bone going out that is why it is called interstitial meaning inside the tissue. What happens is the cartilage grows longer.  When you talk about appositional, it occurs outside the bone, the periphery of cartilage. This happens on pre-existing cartilage making the cartilage thicker. With that, the answer to your question is B.