(d) : Cartilage is a semi-rigid supportive or skeletal connective tissue in which matrix is solid and made of mucoprotein or proteoglycan called chondrin. It is of four types -hyaline, fibrous, calcified and elastic. Yellow elastic fibrocartilage is found in pinna and external auditory canal of the ear, Eustachian tubes, epiglottis and tip of the nose. Its matrix contains numerous yellow fibres which form a network by uniting with one another. Due to the presence of yellow fibres, the cartilage becomes more flexible. Hence, it provides flexibility to these organs.