You’d use Unique Reach and Frequency to measure the number of times people were served your ads and the number of times times they were each served across devices and formats.

• You’d use Viewability with Active View.
• You’d use Brand Lift.
• You’d use Unique Reach and Frequency.
• You’d use Reach Planner.

The correct answer is: You’d use Unique Reach and Frequency.

Explanation: To gauge the effectiveness of your Google Video campaign, which is focused on raising awareness, use unique reach and frequency metrics. These metrics take into account multiple devices and co-viewing, allowing you to assess the number of people who were served your ads and how many times they were each served across devices and formats. Metrics like unique users, average impression frequency per user, and frequency distribution can be viewed by adding columns to your statistics table and selecting a specific time period. Google Ads uses statistical models to deduplicate an audience across different devices and networks, resulting in the number of unique users who saw your ad.

Read more here: https://support.google.com/google-ads/answer/2472714