Courtney receives most of her income from wages from her job as a high school teacher. She also receives supplemental income from freelance tutoring part-time during the summer. Because her tutoring income is not subject to withholding, Courtney is concerned that she will have a balance due at the end of the year. Which of the following is an option you can recommend to Courtney to avoid a balance due?

Claim an exemption from withholding.

Investigate whether she qualifies to classify her tutoring income as a hobby rather than as business income.

Send a notarized letter to her employer requesting that they withhold additional amounts from her pay each month.

Use the IRS Tax Withholding Estimator to determine her estimated tax obligation and complete a new Form W-4 if necessary.