Which of the following was not one of the nation’s three largest cities in 1790

A．because the auction sales took place at night
B．as a signal for the crowd to gather
C．to keep the auction room warm
D．to limit the time when offers of prices could be made

A．for the highest price offered
B．at fixed prices
C．at prices lower than their true value
D．at prices offered by the auctioneer