Answer and Explanation:
Given that this is a second price bid auction whereby the second highest bid is the price that the highest bidder pays for the item up for auction sale, so that b1>b2 then b1 gets item for the price of b2.
Truthfulness of true value is the dominant strategy here which means each player should aim to be truthful with their bid regarding their true value regardless of what other bidders are bidding. Therefore truthfulness of value is the optimal strategy with the best payoff for bidders