Concept:Dealing in quoted securities on the Nigerian Stock Exchange is reserved for licensed stock exchange members called brokers.Explanation:Quoted securities are shares or bonds officially listed for trading on the stock exchange.Members of the public, companies, or investors cannot carry out direct buying and selling on the exchange floor.Only authorized stockbrokers are permitted to deal in these securities on behalf of investors.This restriction helps to maintain orderly and regulated trading activities on the exchange.Answer:B. brokers