Which of the following statements is/are true about secondary market transactions

I. Dark pools are a means to reduce search costs

II. A broker may bring buyers and sellers together, charging a commission

III. A dealer may sell and buy securities using his or her own inventory, therefore reducing search costs

IV. An auction market allocates the selling shares to the highest bidder

A. I and II only

B. II and III only

C. II, III, and IV only

D. I, II, III, and IV