Which of the following is NOT a rule for using a credit card wisely?

The correct response highlights that having at least three credit cards is not a rule for using a credit card wisely. In fact, managing multiple credit cards can complicate one's financial situation. While some individuals may choose to have more than one credit card to enhance their credit score or take advantage of different benefits, it is not a necessary rule for responsible credit card usage.

The other options reflect sound credit card management practices. Paying off the balance each month is crucial as this avoids interest charges and helps maintain a good credit score. Monitoring your credit limit is important to prevent overspending and to ensure that you do not negatively impact your credit utilization ratio. Similarly, using credit cards only for necessary purchases keeps the usage within a manageable range and promotes financial discipline. Thus, the emphasis on responsible credit card usage does not inherently call for the possession of multiple cards.