Question

Which of the following sentences is correctly punctuated?
I have taken notes on your book however I still have questions.
I have taken notes on your book, however I still have questions.
I have taken notes on your book; however, I still have questions.
I have taken notes on your book however; I still have questions.

Answer 1

Option 3 :

I have taken notes on book; however, I still have questions.

Answer 2

I have taken notes on your book,however I still have questions