With TrueView in-stream ads, an advertiser pays:

1. on a cost-per-thousand-impressions (CPM) basis
2. when the viewer watches at least 30 seconds of the video or completes it
3. only when the viewer clicks the video
4. when the viewer watches five seconds of the video

Correct Answer:

• when the viewer watches at least 30 seconds of the video or completes it