The Experience Rate System measures which of the following for the employer?

The Experience Rate System focuses on the relationship between an employer's unemployment claims and their corresponding unemployment tax rate. This system is designed to encourage employers to maintain stable employment levels. Specifically, it measures the amount of unemployment claims filed by former employees against an employer over a specified period. A higher number of claims can indicate that an employer has a higher turnover rate and may lead to an increase in the unemployment tax rate that the employer must pay.

Understanding this system is essential for both payroll management and cost control since employers with lower claims can benefit from lower tax rates, thereby reducing their overall payroll expenses. This concept directly ties into employer liability and financial planning for unemployment insurance taxes.

The other options focus on employee experience in irrelevant contexts, such as job placement or promotion eligibility, which do not pertain to the purpose of the Experience Rate System. Thus, B is the accurate choice as it correctly identifies the essential aspect of the Experience Rate System's measure relating to an employer's unemployment claims activity and its tax implications.