Match the structure listed in column A with the type of cartilage composing the structure, listed in column B.
Column A
1. external ear
2. epiglottis
3. pubic symphysis
4. costal cartilages
5. menisci in the knee
6. auditory tube
7. tracheal "C" rings
Column A
a. hyaline cartillage
b. fibrocartilage
c. elastic cartillage