There is an error in Free Response Question #4 of the online, REA Crash Course exam that comes with the new book. I have sent an amendment to REA today, and hopefully this will be fixed ASAP. Also, the answer to Q6c has a rogue number ‘2’ in front of the H2O.
As Monday is a holiday and bad weather is expected in the North East (home of REA), it may take a little while before this is corrected. Apologies.