Yes, sentence C is correct. The correct punctuation in this case is a semicolon (;). A semicolon is used to separate two closely related independent clauses that are not joined by a coordinating conjunction (e.g., "and," "but," "or"). In this sentence, the independent clauses are "Laura has an Australian dog" and "I have a miniature Schnauzer." The semicolon helps to indicate a stronger connection between the two clauses compared to using a period (full stop) or a comma.