Ans.
Features shared by different organisms are inherited from a common ancestor. A common ancestor of any group of organism is defined as the most recent organism, from which all the individuals are descended directly.
As all four organisms have scales and a backbone, lay eggs, and can walk on land, all these characteristics should be present in their common ancestor, from which they arose.
Thus, the correct answer is 'option). their common ancestor has the same four shared characteristics.'
