By what date must employees send W-2 statements to employees who have had taxes withheld and who are still working for the employer as of December 31st?

The correct answer is January 31st because this is the federally mandated deadline for employers to provide W-2 statements to their employees. The W-2 form details the wages earned and taxes withheld throughout the previous calendar year. Employers are required to furnish these forms to employees who have had income tax withheld, as well as to the Social Security Administration by this date.

This deadline ensures that employees have sufficient time to prepare their income tax returns, as they rely on the W-2 information to report their earnings and tax obligations accurately. Receiving the W-2 by January 31 also coincides with the IRS's guidelines for tax season, making it essential for individuals to file their taxes on time. The other options reflect dates that do not comply with federal regulations, thus highlighting the importance of adherence to the January 31 deadline.