According to the research, the correct option is 3. Bilaterally flattened is a characteristic of a cartilaginous fish.
They are a class of fish characterized by having dermal scales and with widened paired fins whose skeleton is made up of cartilage.
They have a hydrodynamic shape being bilaterally flattened, that is, they are flattened in the dorso-ventral axis, which allows them to do the constant movements necessary to propel those fish through the water and avoid sinking in the water.
Therefore, we can conclude that the correct option is 3. Bilaterally flattened is a characteristic of a cartilaginous fish.
Learn more about cartilaginous fish here: brainly.com/question/1120298
#SPJ1
