Respuesta :
Definitely a is not correct or accurate because a sentence involves a subject or the topic you are reading or referring to and it also has. A predicate which is a verb and thought. B is not the correct answer as well it does not have a compete thought .So that leaves us with c and d so c is an interrogative sentence which is a question plus it has a subject and the correct usage of marks. Definitely d it follows the trend of modern usuage. Think of it on terms of Shakespeare he used words we didn't know or familiar to but we now use it .
Answer:
C: Who are you waiting for?
Explanation:
Preposition means "placing before." The traditional or classical rule requires that prepositions should not end sentences. However, following the trend of modern usage, it is now accepted as a colloquial form. So it is possible to move the preposition to the end of the sentence in questions beginning with a preposition + whom : For whom are you waiting ?/ Who are you waitin for ?