Which of the following are examples of mineralized tissues in (at least some species of) the Chondrichthyes? (Select the single best answer.)
a. Placoid scales (dermal denticles)
b. Regions of the cartilaginous endoskeleton
c. Perichondral bone around regions of the endoskeleton
d. Teeth
e. All of the above
f. None of the above
