Dr. mccall found that student performance was poor when students worked in groups compared to when each student worked on an individual project. in the context of group influence, this difference in performance can be best explained with the concept of:

social loafing

Explanation:

Social loafing:-

It is the concept in social psychology which refers to the phenomenon of a person exerting less amount of effort on a particular task if he/she is in a particular group when compared to the stance when he work alone.

It believes that working in groups helps in improving the quality of the work being accomplished as it will be a amalgamation of the different and unique skills and the talents of each individuals present in the group.

Hence, from the question, the difference of about Dr. McCall found is best explained by the concept  of social loafing.

marginal cost is a microeconomic measure that us to evaluate the extent to which the level of production of a good is sustainable in accounting, that is, to how many quantities the company plans to profit from the production of the good.

the concept of marginal cost is simple, it means the cost of producing one more item. for example, in the case of pies, the marginal cost is the cost of producing one more pie than those that have already been produced.

it is important to understand that productive activity influences marginal cost. the marginal cost of some goods can be very high, while others may be insignificant. for example, the marginal cost of producing an extra plane is very high. already the marginal cost of a water company to provide 1l more water is derisory.

in the case of pies, the cost involves the inputs, the labor and the fixed cost, which involves the fixed space of the bakery. the level of production initially has the marginal cost decreasing because there is space and manpower available. however, to produce more you have to hire more workers and buy more inputs. if physical space is limited, workers will conflict with places, inputs and their productivity will decrease, meaning there is an optimum point of production for each level of space and manpower. from this point on, the productivity of the workers will be getting smaller because of lack of space, so that the marginal cost of producing one more pie will be increasing. so, although you have not posted the chart, but if you have the answer, you can see that my explanation goes according to the marginal cost curve that will increase from the 4th pie, answer (c).

it is a better alternative