Mollusks in class bivalvia a. have two shells. b. lack a "head." c. do not have a radula. d. all of the above

I think it is D

Bivalvia s a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. Bivalves as a group have no head and THEY LACK SOME USUAL MOLLUSCAN ORGANS LIKE THE RADULA and the odontophore. aces. 

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