Which of these is a scope for Custom Metrics?
Explanation: Similar to custom dimensions, custom metrics can have different scopes. Hit-level custom metrics get associated with all the hit level dimensions with which it was sent. Similarly, product-level custom metrics are associated only with the product with which it was sent. The following examples illustrate these two types of custom metrics.
Read more here: https://support.google.com/analytics/answer/2709828#scope