Which of the following is not an exception to the general rule that a buyer cannot get better title to goods than his seller had?
a. A person who buys goods in the regular course of a retailer's business takes free of any interests in the goods that the retailer has given to others.
b. A person who bus goods in the ordinary course of a dealer's business takes free of any claim of a person who entrusted those goods to the dealer.
c. A person who buys goods that he has reason to know are stolen.
d. A person who has a voidable title to goods can pass good title to a bona fide purchaser for value.