Which of the Following Statements Is a Valid Criticism of Wicker's

Which of the following statements is a valid criticism of Wicker's (1969) pessimistic conclusions about attitude-behavior relations?

A) Wicker only looked at 20 studies,
B) Many of the studies he reviewed contained imprecise measures of attitude and behavior,
C) Wicker obtained an average correlation (r = ,35) that was stronger than he labelled it,
D) both Wicker only looked at 20 studies and Many of the studies he reviewed contained imprecise measures of attitude and behavior