Final answer:
Listening to a dissenting group member's opinions is NOT a symptom of groupthink.
Step-by-step explanation:
In the given options, the symptom of groupthink that is NOT listed is d) Listening to a dissenting group member's opinions. Groupthink refers to the modification of the opinions of individuals in a group to align with perceived group consensus. This often leads to the suppression of dissenting viewpoints and the belief that the group can do no wrong. Therefore, listening to a dissenting group member's opinions is not a symptom of groupthink.