Professor chadwick evaluated a graduate student's research proposal negatively simply because he had heard a rumor about the student's incompetence. when later informed that the rumor had been patently false, the professor's assessment of the student's research proposal remained almost as negative as it was originally.
this best illustrates:

a. the representativeness heuristic.
b. the availability heuristic.
c. belief perseverance.
d. framing.

c. belief perseverance.

Explanation:

Belief perseverance: The term belief perseverance is also referred to as belief persistence. It is defined as an individual's inability to alter or change his or her belief even after receiving some new facts or information that hinders the previously existing beliefs.

An individual experiencing belief perseverance stick to their thoughts and beliefs even after encountering he or she shouldn't be doing that.

In the question above, the statement signifies the belief perseverance.

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).

for many centuries there were important factors which the economies of the muslim empires developed increasingly. they applied economic procedures in production, investment, finance, taxation and property. they used to tax certain goods (for example: harvest), they charged interest on money lent, they signed contracts with merchants; they relied on a common currency, and they used checks as well as promissory notes. with the money collected by means of taxation, the government provided the needy with an income. in addition, trading networks covered huge distances, so far regions started to have contact and exchange goods. this trade network covered areas of asia, africa and europe.