Which of the Following Statements Best Explains the Difference Between

Which of the following statements best explains the difference between an agent and a broker-dealer?

A) An agent is an individual who represents a broker-dealer or an issuer and buys and sells securities he does not own in return for a commission on the transactions he executes. A broker-dealer may also buy and sell securities for his own portfolio, in which case the broker-dealer enjoys any price appreciation on those securities.
B) A broker-dealer must be licensed in the state in which he conducts business, but there are no separate licensing requirements for agents.
C) Agents are engaged exclusively in the purchase and sale of stocks whereas broker-dealers also buy and sell bonds and option contracts.
D) Agents conduct their business exclusively in the secondary market, while broker-dealers also operate in the primary market.