Which of the following is considered a variable expense in a budget?

A variable expense is an expenditure that can change from month to month based on usage or personal choices, which is why clothing is considered a variable expense in a budget. Clothing costs can fluctuate widely depending on individual needs and desires, seasonal purchases, and shopping habits. This means that while a person may spend more one month on clothing due to new styles or necessities, they might spend less in another month, demonstrating the inherent variability of these expenses.

In contrast, rent is a fixed expense that typically remains the same each month, providing stability in budgeting. Contributions to a 401(k) plan and auto loan repayments are also fixed obligations that generally do not change month-to-month, making them predictable and more rigid in terms of budgeting. Thus, clothing stands out as the correct answer because of its nature of variability in expenditure.