Final answer:
In 2018, the maximum amount of Social Security tax that an employer must report and deposit for an employee was on the first $128,400 of the employee's wages. Employers paid a rate of 6.2% on these wages for Social Security tax.
Step-by-step explanation:
The maximum amount of Social Security tax that an employer must report and deposit for an employee in 2018 is based on the wage base limit for Social Security taxes, which changes annually. In 2018, the Social Security wage base limit was $128,400. This means that an employer is responsible for paying Social Security taxes at a rate of 6.2% on employee wages up to this limit. Any wages earned above $128,400 were not subject to Social Security taxes that year.
Therefore, the correct answer to the student's question is d) $128,400. This is the maximum amount of wages subject to the Social Security tax for which employers were responsible for reporting and depositing in 2018.