A predicate nominative is the first noun following a linking verb, such as to be (or could be in this sentence). Having this in mind, the predicate nominative is the word planet.
Answer:
Hyperbole, from a Greek word meaning "excess," is a figure of speech that uses extreme exaggeration to make a point or show emphasis. It is the opposite of understatement. You can find examples of hyperbole in literature and everyday speech.
Your answer is C, emissions!