Which action is essential for an insurer to assess risk?

Field underwriting is crucial for an insurer to assess risk because it involves the preliminary evaluation of an applicant's health, lifestyle, and insurability prior to the formal underwriting process. This practice allows underwriters to gather important information directly related to the applicant, such as medical history, occupation risks, and hobbies that might impact the potential for loss. By conducting field underwriting, insurers can make informed decisions on whether to accept or decline an application and what premiums to charge based on the observed risk level.

Other options do not serve the primary purpose of risk assessment. Processing the application immediately may not provide adequate time for thorough evaluation. Providing agent commission details is more related to the business side of insurance rather than risk assessment. Finalizing the policy without proper verification would hinder the insurer's ability to appropriately evaluate the risks involved. Thus, field underwriting stands out as the necessary step for comprehensive risk assessment.