Answer:
The answer is indeed letter C) devastating.
Step-by-step explanation:
Devastating is a present participle. Present participles are formed by adding -ing to a verb, and they can be used as adjectives to indicate that someone or something causes a certain feeling or reaction over someone or something else. For example, from the verb "to exhaust", we can form the present participle "exhausting". If a marathon is exhausting, it means it causes that feeling, it makes people incredibly tired (exhausted).
In the sentence "A devastating fire swept through the valley", "devastating" is the adjective modifying the noun fire. The fire now has a quality - it causes devastation.