Answer: Social loafing
Step-by-step explanation:
Social loafing is described as the mechanism in which people tend to show less effort and working towards a project or activity while working in a group in comparison to working individually.Low motivation, people working as individuals in group etc.
According to the question, social loafing is seen through scenario as Amanda is less interested in group project because she is not motivated to put her effort.As it is a group task everyone will receive same grade so, Amanda also receives same grade as other members.