which type of sentence is this? the weather forecast had predicted severe thunderstorms, but the dark, heavy…

which type of sentence is this? the weather forecast had predicted severe thunderstorms, but the dark, heavy thunderclouds never materialized. simple compound complex compound - complex
Answer
Brief Explanations:
A compound sentence has two independent clauses joined by a coordinating conjunction (in this case, "but"). The two independent clauses are "The weather forecast had predicted severe thunderstorms" and "the dark, heavy thunderclouds never materialized".
Answer:
B. compound