Consider an auctioneer who is selling an item through an auction. It is known that the 25 risk-neutral bidders have affiliated values that are distributed between $0 and $500 million. Based on this information, the auction type that will maximize expected revenue is:____.
1. English auction.
2. second-price, sealed-bid auction.
3. first-price, sealed-bid auction and Dutch auction.
4. English auction and second-price, seal-bid auction.