Final answer:
If United Company pays the hospitalization insurance premiums, lower-paid employees' after-tax and insurance pay will increase more than that of higher-income employees due to their lower marginal tax rates.
Step-by-step explanation:
If United Company decides to pay the employee's hospitalization insurance premiums, the impact on the employee's after-tax and insurance pay will differ based on their marginal tax bracket. For lower-paid employees who are in the 10% and 12% marginal tax brackets, their after-tax income would increase more compared to the higher-income employees in the 35% marginal tax bracket. This is because the premiums paid by the employer would not be taxable income for the employee, effectively becoming a tax-free benefit. For higher-income employees, the benefit would still be tax-free, but because their marginal tax rates are higher, each dollar of premium paid by the employer saves them more in taxes compared to lower-paid employees.
Therefore, the correct answer is: B. Increase more for the lower-paid employees (10% and 12% marginal tax bracket).