Final answer:
The term 'pluralistic ignorance' refers to a situation in a group where individuals mistakenly believe their thoughts or behaviors differ from the group, causing bystander apathy by assuming others will intervene or don't see it as an emergency.
Step-by-step explanation:
The correct answer is b. pluralistic ignorance. This term refers to a situation where individuals in a group mistakenly believe that their own personal thoughts, feelings, or behaviors are different from those of the group as a whole. In the context of bystander apathy, pluralistic ignorance can occur when individuals assume that others in a group perceive a situation as non-emergency or believe that someone else will intervene, which leads them to refrain from taking action themselves.
In contrast, diffusion of responsibility describes a situation where each individual feels less responsible to act because of the number of people present. Social loafing is when individuals exert less effort on a task when working in a group compared to when they work alone. Lastly, herd mentality is the inclination for individuals in a group to follow what the majority is doing.