Answer:
An example of how language can be divisive is the dominance of French in Quebec and English in the rest of Canada.
Step-by-step explanation:
A is not correct because it simply describes a family of closely related languages, which is unifying more often than not, not the other way around.
B is not correct because this statement is not true, as the United States, as all countries in the world, has official language/s.
C is correct because here we have a situation where within one country there are two dominant languages, and the people also use them in order to distinguish themselves from the others, causing tensions in the process, as well as movements toward separation.
D is not correct because such a thing may or may not be problematic, as we do have examples of both around the world.