I would recommend NOT retaking it but before taking A&P II, I would watch a semester's worth of A&P I lectures from UC Berkeley online. Do a search here on allnurses.com for webcast of UC Berkeley's A&P. I have been watching them and they're very interesting! The professor (Dr. Marian Diamond) is an excellent teacher. The only reason I don't recommend retaking I is money. But if you have it to burn, by all means!
I wish I had the link for you but it's bookmarked on my laptop (I'm on my desktop).
Best of luck!