Question 4
Which one is a true fish?

(a) Jellyfish
(b) Starfish
(c) Dogfish
(d) Silverfish

(c) Dogfish

Dog fish is a true fish because it belongs to class-Chondricythes i.e., Pisces (phylum chordate). Jellyfish belongs to phylum Cnidaria. Starfish are star shaped echinoderms, which are marine invertebrates which have a central disc and five arms. Silver fish is small wingless insect belongs to phylum-Arthropod.