When determining WC premiums, which factor is critical for assessment?

The critical factor for assessing workers' compensation (WC) premiums is claims history and work classifications. This is because the claims history provides insight into the frequency and severity of past employee injuries within the company, which can indicate the level of risk associated with the employer's specific industry. Higher claim rates typically lead to higher premiums because insurers view such businesses as more likely to incur costs related to workers' compensation claims.

Work classifications also play a significant role as they categorize the type of work activities and associated risks. Different industries and job types have established classification codes that correspond to different rates of premiums based on risk levels. Hence, a construction company may face a higher premium compared to a clerical office due to the inherent risks in construction work.

While the other options may influence a company's overall risk profile or operational context, they are not as directly tied to the establishment of WC premiums as claims history and work classifications are.