______ is an Amazon Ads solution that allows advertisers to pro grammatically buy ads to help reach new and existing audiences where they spend their time.

The correct answer is Amazon DSP because this solution enables advertisers to programmatically purchase ads across various digital platforms, effectively reaching both new and existing audiences wherever they engage with content. Amazon DSP allows for sophisticated targeting and retargeting strategies, leveraging Amazon's extensive data to optimize ad placements and enhance campaign performance. In contrast, the audience planning tool is focused on helping advertisers understand and define their target demographics, while the campaign manager is primarily used for managing ad campaigns within Amazon's advertising ecosystem, making Amazon DSP the most suitable option for programmatic ad buying.