Which of the following best describes the outcome for the Smiths if they do not increase their investment in the prepaid tuition plan despite rising costs?

If the Smiths do not increase their investment in the prepaid tuition plan while costs continue to rise, the most appropriate description of their outcome is that the plan may be insufficient.

Prepaid tuition plans are designed to allow families to pay for college tuition at today's rates, essentially locking in the cost before the actual enrollment occurs. However, if the costs of tuition and associated fees increase and the Smiths do not augment their contributions to the plan, the original amount they invested may not cover the total future costs of tuition. This situation highlights the potential inadequacy of their prepaid plan to meet rising educational expenses, leading to possible shortfalls when the Smiths are ready to access the funds for tuition payments.

An increase in costs can happen due to various factors, such as inflation or changes in university funding policies, making it essential for families to reassess the adequacy of their investments in light of such economic changes.