Which of the Following Statements About Research on Persuasion Is

Which of the following statements about research on persuasion is true?

A) Older people are more likely than younger people to change their attitude.
B) Television is a more powerful medium for persuasion than a printed newspaper.
C) People who have initially strong attitudes on an issue are more likely to be persuaded than those with initially weak attitudes.
D) Emotional appeals are usually not very powerful means of persuasion.