A "Continuous Double-Auction" Is One Where

A "continuous double-auction" is one where:

A) Buyers submit bids and sellers submit asks; individual buyers and sellers are free to engage in decentralized trading in order to find profitable trades.
B) The buyer bids and seller asks are aggregated in order to create the underlying demand and supply curves respectively; all trade takes place at the equilibrium price dictated by the underlying demand and supply curves.
C) Sellers post prices and buyers are welcome to buy or not on a take-it-or-leave it basis.
D) Asks must be ascending; they start low and go up; bids must be descending; they start high and go down.