Which of the following statement is true ?

Options

A. All living members of class cyclostomata are parasites on some fishes
B. There are about 2,000 species in the class osteichthyes
C. Ciona belongs to the subphylum cephalochordata
D. Arthropods are diplobastic animals

Answer

A

Explanation

All living members of class cyclostomata are ectoparasite on some fishes and suck blood from them