Because yuri was curious about human behavior, he enrolled in an introductory psychology course. george registered because he heard it was an easy course that would boost his grade-point average. in this instance, yuri's behavior was a reflection of whereasgeorge's behavior was a reflection of
a. operant conditioning; classical conditioning
b. intrinsic motivation; extrinsic motivation
c. an unconditioned response; a conditioned response
d. a fixed-interval schedule; a variable-interval schedule

B. intrinsic Motivation; extrinsic motivation        

Explanation:

Intrinsic Motivation: It is defined as the process of executing a behavior or an action by an individual because he or she enjoys the activity. The individual gets the inspiration for acting himself or herself.

Example: A child plays the football match because he loves playing it rather than thinking to get an award after winning the match.

Extrinsic motivation: It is defined as the behavior of a person that is operated by external rewards, for example, fame, praise, money, and grades. In this case, the motivation originates from outside of the person.

Example: A person is doing a job because he is getting paid for the job.

The instance given in the question above, Yuri's behavior was a reflection of intrinsic motivation, whereas George's behavior was a reflection of extrinsic motivation.

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).