Final answer:
The tax paid exclusively by employers and not deducted from employees' wages is 'a. Unemployment, which funds unemployment benefits for workers who lose their jobs.
Step-by-step explanation:
Employers bear the responsibility for multiple payroll taxes linked to their employees' compensation. These encompass deductions from wages and taxes exclusively allocated to the employer. Typically, payroll taxes include federal and state taxes, along with contributions to Social Security and Medicare.
Notably, unemployment insurance stands out as the sole payroll tax exclusively funded by the employer, without any deduction from the employees' wages. This tax contributes to a fund designed to aid workers facing job loss, offering support for up to six months. In summary, among the payroll taxes, only unemployment insurance, identified as option "a. Unemployment," is shouldered solely by the employer, playing a crucial role in assisting workers navigating periods of unemployment.