Most fish do not sink in water because of the presence of: I. swim bladder II. air bladder III. air sacs IV. air in spongy bones A. I and II are correct B. II and III are correct C. III and IV are correct D. I, II, III and IV are correct
Fishes have a swim bladder or air bladder which helps them to remain buoyant without sinking in water. They are present in the body cavity.
A
A option is correct
