Which among the following is not a class of phylum $Mollusca$?

Which invertebrate phylum exhibits unisexual or hermaphrodite conditions,external or internal fertilization,and direct or indirect development?

$A$ shell of calcium carbonate,a mantle,and a radula are characteristic features of which of the following?

The most active animal among the phylum $Mollusca$ is ........

In $Mollusca$,the radula is a part of the:

$Pila$ shows summer: