An advertiser has a newly launched awareness campaign. The campaign is meeting its goal, but isn't spending the budget in full with a strict frequency cap and interest targeting. Which optimization tactic should the advertiser use?

The selected answer is correct because a strict frequency cap combined with narrow interest targeting can create a delivery bottleneck by severely limiting the pool of eligible users and how often they can see the ad. By loosening frequency caps and expanding targeting to include broader interests or related keywords, the advertiser increases the number of available impressions in the auction, allowing the system to spend the full budget while still maintaining the campaign's awareness goals.