Which of the following best explains ways in which fish and mammals differ?

The one that best explains ways in which fish and mammals differ is : fish are ectothermic and lays eggs to reproduce, while mammals are endothermic and give birth to offspring

The 'common fish' that give birth to its offspring such as whales and dolphins are considered mammals

hope this helps

Tta ttc ctg i hope its right.

The category is the thing that is most simmilar throughout a period