The correct option is A Calcified cartilage
In the frog, there are three parts of hip bone: ilium, ischium and pubis. The pubis is a triangular mass of hyaline and in older frogs is the calcified cartilage on the ventral side of the pelvic girdle. It means that the cartilage contains deposited calcium salts.
Thus, the correct answer is option (A), 'Calcified cartilage'.