Answer:
The online dictionary suggests the following:
C. The word is Greek in origin.
Step-by-step explanation:
After reading the three definitions of "theater", we can see the word did not change meanings that much. All in all, it refers to a space where dramatic performances, be them live or not, take place.
The dictionary entry does not show a change in word category. The word is just a noun. It also implies nothing related to Vikings.
The correct answer is letter C. The entry implies that the word theater is most likely Greek in origin, since it was used in ancient Greece and Rome.