​Which of the following statements is incorrect?   a….

​Which of the following statements is incorrect?   a.  ​Exchange-traded funds (ETFs) are designed to mimic particular stock indexes and are traded on a stock exchange.   b.  ​ETFs have very high expense ratios.    c.  ​ETFs differ from most open-end and closed-end funds in that they are not actively managed.   d.  ​One disadvantage of ETFs is that each purchase of additional shares must be done through the exchange where they are traded.   ANSWER:   b POINTS:   1 DIFFICULTY:   Challenging