What best describes Enhanced Cost-Per-Click (ECPC)

What best describes Enhanced Cost-Per-Click (ECPC)

A) ECPC is a separate bid set for ad groups using the Conversion Optimizer
B) ECPC is a CPC bidding feature that automatically bids more aggressively in auctions more likely to result in a conversion
C) ECPC is a Quality Score boost for advertisers using ad extensions
D) ECPC is the discount applied to your Max CPC to determine actual CPC

Answer - ECPC is a CPC bidding feature that automatically bids more aggressively in auctions more likely to result in a conversion