Match the sponsorship purchase methods to the descriptions.

Advertisers are able to bid against other advertisers for ad spots based on a wider range of actions such as impression, video view, or an engagement, where the highest bidder wins the spot. (3)
Advertisers pay a predetermined fixed rate for an ad spot. This is a fixed CPM method of purchase. (1)
Allows advertisers to verify that their ads are reaching a specific demographic via Nielsen. You are only charged for impressions that serve that specific demographic as verified by Nielsen third-party reporting. (2)