A retail advertiser wants to drive awareness about a new product launch to reach people on Pinterest who saved Pins from its previous spring campaign. Which type of audience targeting is required to meet this objective?

The correct answer is Engagement. An Engagement Audience allows advertisers to retarget users who have previously interacted with their content on Pinterest, such as saving Pins. In this scenario, the advertiser wants to reach people who saved Pins from a previous campaign, which directly corresponds to an engagement action. Customer List audiences are created by uploading a list of customer emails or IDs, which isn't specified here. Actalike (Lookalike) audiences find new users who share similar characteristics with an existing audience, not users who have already engaged. Site visitor audiences target users who have visited the advertiser's website, which is different from engaging with Pins on Pinterest.