The requirements specify that we need to select book titles based on a price condition and a date condition, and then sort the results by the date of purchase.

A. This query will not execute successfully because there is a syntax error in the price condition. It should be price < 500 OR price > 1000.

B. This query is incorrect. The requirement specifies that the price must be less than 500 or more than 1000, not in a list of values.

C. This query is correct. It selects books where the price is not between 500 and 1000 (thus, less than 500 or more than 1000) and the purchase date is before January 17, 2007, ordered by purchase date in descending order.

D. This query is incorrect because it selects books with prices between 500 and 1000, which is not what the requirement specifies.