What’s the difference between cost-per-click (CPC) bidding

What’s the difference between cost-per-click (CPC) bidding and cost-per-view (CPV) bidding?

A) The advertiser pays for a click on an ad with cpc bidding. and pays for a conversion with cpv bidding.
B) The advertiser pays for a click on an ad with cpc bidding. and pays when a user watches a video with cpv bidding.
C) The advertiser pays for a click on an ad with cpc bidding. and pays for a video impression with cpv bidding.
D) The advertiser pays for a click on an ad with cpc bidding. and pays every time a user sees a video with cpv bidding.

Answer: B