Joseph sees money fall out of a stranger's pocket and returns it to the rightful owner. He believes ...

Joseph sees money fall out of a stranger's pocket and returns it to the rightful owner. He believes it would be dishonorable to keep money that is not his own and assumes that most others share this view.
 
  Which of the following may explain why Joseph could be incorrect in his assumption?
  a. Joseph is failing to notice information that confirms his belief.
  b. Joseph is not spending enough time thinking about his own views.
  c. Joseph is not considering that others may have a different idea of what it means to be dishonorable.
  d. Joseph is not incorrect in his assumption.