the letter B. that is the answer
As you can see the structure of the entire go have changed from a low set posture to a rounded figure. you can also see changes in the jaw shape and the bed of the school you can also see different dynamics in the dents etc within the skull . as you can see the beginner skull is reminiscent of animalistic features and crude shaping.
Two reasons Eugleoids are considered to be animal-like is because they can move from one place to another, and are heterotrophic (consumes food made by other organisms) or >> reproduces by fission << could be another option.