I'd say answer the first answer choice...
The first sentence is correct.
Answer:
because, because of, since, consequently, therefore, as a result ......
Explanation:
The answer that is a correctly punctuated compound sentence is option a. this book was very long; i liked it anyway. In this compound sentence, the punctuation mark semicolon is used. Aside from using coordinating conjunctions to connect two independent clauses in a compound sentence, a semicolon can be used as well.