In general, people who are are more likely to use the central route when attending to a persuasive communication.
a. low in need for cognition.
b. high in need for cognition.
c. not involved in the issue in question.
d. ambivalent about the issue in question.

Option(b) is correct

Explanation:

According to the question, high in need for cognition people are indulged in information seeking acts to attain information and involve in thinking. In terms of persuasive communication, high need for cognition is required for convincing other person through thinking and information.

Other options are incorrect because low requirement of cognition, ambivalent and no involvement in case is not method used by person in persuasive communication. Thus, the correct option is option(b).

sounds good to me mate!