Most fish do not sink in water because of the presence of the
(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
The correct option is: (a) i and ii are correct
