The only incorrectly matched pair is:

Phylum	Level of organisation

$A$ blastula which is solid,is known as

What is common between $Ascaris$ $lumbricoides$ and $Anopheles$ $stephensi$?

Give an example of the following:
$(a)$ $A$ viviparous animal
$(b)$ $A$ fish possessing a poison sting
$(c)$ $A$ fish possessing an electric organ
$(d)$ An organ which regulates buoyancy
$(e)$ An animal which exhibits alternation of generation
$(f)$ An oviparous animal with mammary glands

Trochophore larva is found in

Which of the following represents the correct combination without any exception?
Characteristics - Class