William, given that there are several purchases he didn't make, is a victim of B. Credit card fraud.
William is a victim of credit card fraud because he discovered unauthorized purchases on his credit card statement that he did not make. Credit card fraud involves the unauthorized use of someone else's credit card information to make purchases or transactions without their knowledge or consent.
In this scenario, someone used William's credit card details to make purchases without his permission, which constitutes credit card fraud. It's different from identity theft because it specifically involves fraudulent use of the credit card, not necessarily the theft of his entire identity.