In Each of the Following Sets, Select the Sentence That

Multiple Choice

In each of the following sets, select the sentence that uses the correct coordinating or subordinating conjunction and that is punctuated correctly. Which sentence uses the correct coordinating or subordinating conjunction and is punctuated correctly?

A) I think Dion is a hopeless romantic. Because he plays his guitar beneath his girlfriend's window every night.
B) I think Dion is a hopeless romantic because he plays his guitar beneath his girlfriend's window every night.
C) I think Dion is a hopeless romantic; because he plays his guitar beneath his girlfriend's window every night.