which type of sentence is this? variations of bowling have existed for centuries, but a standard form of the…

which type of sentence is this? variations of bowling have existed for centuries, but a standard form of the game wasnt established until various regional bowling clubs formed the american bowling congress in 1895. simple compound complex compound - complex
Answer
Brief Explanations:
A compound sentence has two independent clauses joined by a coordinating conjunction like "but". Here, "Variations of bowling have existed for centuries" and "a standard form of the game wasn't established until various regional bowling clubs formed the American Bowling Congress in 1895" are two independent clauses joined by "but".
Answer:
B. compound