Which of the following actions can increase the APR (annual percentage rate) applied to your credit card account?

Introduction / Context:
Credit card issuers disclose an annual percentage rate, or APR, which represents the cost of borrowing on the card if you carry a balance. Under many card agreements, this APR can change based on how you manage the account. In particular, missing payments or repeatedly paying late can lead to a higher penalty APR. This question asks you to identify which behaviour is likely to cause your credit card APR to increase, rather than remain stable or even be reduced over time.

Given Data / Assumptions:
- The subject is a consumer credit card account. - We are considering behaviours such as making payments on time, missing payments and not using the card. - The focus is on what can increase the APR charged by the issuer. - We assume a typical card agreement that includes a penalty APR for serious delinquencies.

Concept / Approach:
Credit card companies assess the risk of each customer and price that risk in the form of APR. Responsible behaviour, such as paying at least the minimum amount on time every month, generally helps keep the APR stable and may even lead to better offers in the future. Missing payments or paying significantly late is a warning sign of higher risk. As a result, many issuers reserve the right to increase the APR to a higher penalty level after one or more missed payments. Simply not using the card, by itself, usually does not cause an APR increase, although very long inactivity may eventually lead the issuer to close the account. Therefore, the behaviour that can increase the APR is missing or late payments, not regular on time payments or non use.

Step-by-Step Solution:
Step 1: Evaluate option A. Making payments on time demonstrates good credit behaviour and does not justify a higher APR, so this option does not increase the APR. Step 2: Evaluate option B. Missing payments or paying late is a violation of the card terms and may trigger penalty pricing, so this option can increase the APR. Step 3: Evaluate option C. Not using the card may lead to account closure or reduction of credit limit but does not typically result in an APR increase by itself. Step 4: Since only option B describes a behaviour that can directly cause an APR increase, option D, which includes all actions, must be rejected.

Verification / Alternative check:
If you read the pricing and terms of most credit card agreements, you will find a section describing penalty APR. It often states that if you make a late payment or your payment is returned, the issuer may increase your APR to a higher level. There is usually no clause that increases APR because you pay on time or because you simply do not use the card. At most, non use may lead to account closure for inactivity. This confirms that missing payments is the behaviour that can raise your APR.

Why Other Options Are Wrong:
Making payments on time: This is positive behaviour and is often rewarded with fee waivers or promotional offers, not punished with a higher APR. Not using the card: Inactivity may affect the issuer decision about keeping the account open, but it is not a reason to increase the borrowing rate. All of the above: This would be correct only if all listed actions could increase the APR, which they do not.

Common Pitfalls:
Some cardholders believe that issuers raise APR arbitrarily regardless of behaviour, which can create unnecessary fear or confusion. While market conditions and risk based pricing can change rates, the most direct behaviour under the customer control is payment discipline. Another pitfall is thinking that minimum payments are enough to avoid all negative consequences. Even if you avoid late fees, carrying high balances can still be costly due to interest charges, but it is late or missed payments that typically trigger penalty APRs. For exam purposes, associate APR increases primarily with missed or seriously late payments.

Final Answer:
The correct option is Missing credit card payments or paying late, triggering penalty pricing, because this behaviour signals higher risk to the issuer and can cause the APR on the card to increase to a penalty rate.