________ is used for video campaigns.

A) Cost-per-click (CPC) bidding
B) Cost-per-thousand-impressions (CPM) bidding
C) Cost-per-view (CPV) bidding
D) Cost-per-acquisition (CPA) bidding

The correct answer is:

C) Cost-per-view (CPV) bidding

Explanation: Cost-per-view (CPV) bidding is the default way to set the amount you’ll pay for TrueView video ads in AdWords. With CPV bidding, you’ll pay for video views or interactions (such as clicks on call-to-action overlays, cards, and companion banners). A view is counted when someone watches 30 seconds of your video ad (or the duration if it’s shorter than 30 seconds) or interacts with the ad, whichever comes first.

Read more here: https://support.google.com/adwords/answer/2472735?hl=e