Answer:
D. open outcry
Explanation:
At a trading floor, a trader is the person who sell or buy securities such as equity, commodities, fixed income, or foreign exchange on behalf of their employer. During this trading, traders verbally submit their offers and this type of trading is called open outcry.
Open outcry can be defined as a means of communication on a trading floor. Traders shout and use hand signals to tell their partners to buy or sell the stock.
Hence, the correct answer is "D. open outcry"
