I do not know the answer but I think it might be D. or A.
The answer is C that planets and stars moved in the sky
Speaking a language sets human beings from other animals reason being,
1. We can use abstract. For example, future and past.
2. We can borrow words from different languages.
3. We can be able to invent languages.
Linguist refers to a person who uses languages. He is able to analyse the language context, meaning and its form.
Linguist is well known to analyse language of human beings by way of observing a play between the meaning and the sound.
A, this is because they have just gone through the Civil War and now they need to reconstruct the land and government