Consider a first-price sealed-bid auction with three players: Betsy (B), Daniel (D) and Michael (M). Their
valuations are vB = 100, vD = 90, and vM = 30, respectively. If their bids are bB = 90, bD = 30, and bM = 0, respectively, show that this NOT a Nash equilibrium. Do not construct a game box in justifying your answer. Do not make any assumptions about the distribution of bidders' valuations.