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

What’s the difference between cost-per-click (CPC) bidding and cost-per-view (CPV) bidding?
  A)  The advertiser pays for an impression on an ad with CPC bidding, and pays when a user watches a video ad with CPV bidding.
  B)  The advertiser pays for a click on an ad with CPC bidding, and pays when a user watches a video ad with CPV bidding.
  C)  The advertiser pays for a click on an ad with with CPC bidding, and pays for a video ad impression with CPV bidding.
  D)  The advertiser pays for a click on an ad with CPC bidding, and pays for a conversion with CPV bidding.