The single most important influence that shaped the founding of United States comes from John Locke a 17th century Englishman who redefined the nature of government
The correct answer is B. Trust, competence and ethos.
The speaker will inspire credibility from the audience when it perceives his or her character and their ethos concerning the topic they are presenting. If they know it really well, they will speak with authority, which will engender trust. Their competence is manifested and it's easier for the audience believe and received what it's being conveyed.