Which of the following payments may be included in an employee's taxable wages?

The inclusion of cash bonuses in an employee's taxable wages is grounded in the fact that bonuses are considered additional compensation for work performed. The IRS classifies bonuses as supplemental wages, which are fully subject to income tax withholding, Social Security taxes, and Medicare taxes. This means they directly contribute to the employee's taxable income and must be reported on their tax returns.

In contrast, other benefits such as transportation provided for personal use, health insurance premiums paid by the employer, and childcare benefits may be excluded or have special tax treatment. For example, employer-paid health insurance premiums are typically not included in taxable wages, as they are a benefit that employees do not have to report as income. Similarly, many childcare benefits can fall under specific tax exclusions or credits, offering tax advantages to both employers and employees.

Thus, cash bonuses stand out as a clear example of taxable compensation, leading to their inclusion in an employee's taxable wages.