Custom metrics can only have two scopes Hit level scope and Product level scope. If a Custom Metric has a Hit level scope then, the value of the custom metric is applied only to that hit with which the value was sent. If a custom metric has a Product level scope then, the value of the custom metric is applied only to the product for which the metric has been set.
This question is a part of the Google Analytics Individual Qualification. You can get all the answers with detailed explanation for this exam in our Google Analytics Individual Qualification Exam Answers page.