Answer D) Radiation
Answer comes from diagram shown in question
The tapeworm is a parasite, and the dog is a host.
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.
