C. It can demonstrate that the character is from a different place of time.
Syntax basically means how a well-formed sentence is put together and like most parts of language, is something that changes based on place and time period. Therefore the choices A, B and D doesn't make sense as answers. The arrangement of words has changed a lot since the 15th century after all, and so might the syntax change as well if you went to another country. So if a character uses a certain syntax, it might show that the character is from a different place or time.
