In the Study by Petty, Cacioppo and Goldman (1981) in Which

In the study by Petty, Cacioppo and Goldman (1981) in which students were exposed to an attitude-discrepant communication, the results showed that:

A) under low involvement, the strong arguments led to much more attitude change than did the weak arguments
B) under high involvement, the source credibility had a stronger effect on persuasion
C) source credibility had a stronger effect on persuasion under both high and low involvement conditions
D) under low involvement, the source credibility had a stronger effect on persuasion
E) both a and b