Which of the following statements is/are correct? a. Whales do not have gills. b. Special breathing organs like gills in fishes are present to help them survive under water. c. Fishes develop scales or waxy coating to reduce friction and help in swimming.

These statements are correct. Some sea animals like whales and dolphins do not have gills. They breathe in air through their nostrils or blowholes and they can stay underwater for a long time without breathing. For breathing they come out of the water from time to time. Special breathing organs like gills in fishes are present to help them survive under water.