Answer: the Specialist/DMM has therefore guaranteed $25 to the trader.
Explanation:
A floor broker is simply referred to as an exchange independent member who acts as a broker for members who are being overloaded with orders
A floor broker enters the crowd around the Specialist's (DMM's) post to buy 20,000 shares of ABC at the market for a public customer. The Specialist (DMM) tells the trader "20,000 shares of ABC have been stopped at 25." This means that the Specialist/DMM has therefore guaranteed $25 to the trader