Are These Correct?

18. Which of the following shows correct semicolon usage?

A. The rally is today, however; Janet isn't going.

B. The rally; is today, however, Janet isn't going.

C. The rally is today; however, Janet isn't going.

D. None of the above

I think the answer is A

19. Which of the following is correct?

A. Bill had been shopping for hours, finally, he found the book he wanted.

B. Bill had been shopping: for hours, finally he found the book he wanted.

C. Bill had been shopping for hours; finally, he found the book he wanted.

D. None of the above

I think the answer is D

20. Which of the following is correct?

A. Dave neglected to study for the exam; consequently, he recieved a poor grade.

B. Dave neglected to study for the exam, consequently he recieved a poor grade.

C. Both A & B

D. Neither A nor B

I think the answer is C

Thanks for all the help