Which of the following statements about source credibility is true? select one: a. the stronger the perceived qualifications and expertise on the subject matter, the lower the credibility. b. people appear more or less credible because of their "presence." c. trustworthiness, and how qualified the person appears to be, are less powerful characteristics in determining our perception of another's credibility than the type of person the source is. d. when meeting others they don't know, people generally tend to evaluate them negatively rather than positively. e. all of the above statements about source credibility are true.