What is the correct permission to grant an advertiser who wants to access their ad account only to see reports?

Granting the Ad Account Analyst permission allows an advertiser to access the ad account specifically for the purpose of viewing reports. This role is designed for users who need insights into ad performance without having the ability to make any changes to the ad campaigns or account settings. Analysts can generate and examine reports to assess the effectiveness of various ads, monitor metrics, and gather data-driven insights that can inform future marketing strategies.

In contrast, the other roles would provide access to additional capabilities beyond just viewing reports, such as managing ads or making changes, which is not suitable for someone who only requires reporting access.