Q: The fact that all animals have certain traits in common shows that they share what?


Read this paragraph and choose the correct option from the provided answers:

There is great variation among species that make up the animal kingdom. Some of this variation is shown in Figure below . Despite the variation, there are a number of traits that are shared by all animals. The fact that all animals have certain traits in common shows that they share a common ancestor. How did such a diverse group of organisms evolve? What traits do all animals share? Read on to find out.

 Choices:

- a common gene

- a common brain

- a common planet

- a common ancestor


A:
a common ancestor