How do you check for custom dimensions related to UTM tags in Google Analytics?

• A. Open the Admin settings and enable 'UTM Dimensions'.
• B. Click the configure icon in the navigation panel and select 'Custom definitions,' where you can view the custom dimensions.
• C. Use the GA4 API to fetch 'UTM' objects.
• D. In Reports, filter by 'UTM custom dimensions'.

Answer: (B)

Viewing custom dimensions in Google Analytics 4 is where you confirm how UTM parameters are captured. Custom definitions hold user-created dimensions and metrics that map to data collected on events. To check if UTM values are being captured as a custom dimension, open the left-hand navigation, click Configure, then select Custom definitions, and open Custom dimensions. You’ll see your defined dimensions, including their names, scope (usually event), and the parameter they map to (for UTMs like utm_source, utm_medium, utm_campaign, and so on). If you need to create one, add a new custom dimension and set its parameter to the UTM name. This is the right place because GA4 doesn’t have a single built‑in display for UTMs; you view and manage how you map them to dimensions here. The other options aren’t as fitting: there isn’t a simple switch called “UTM Dimensions,” the API is for programmatic access, and filtering in Reports relies on existing dimensions rather than showing how they’re defined.