One of the following is not a requirement of experimental design:.
A) Multiple measures must be taken before and after exposure to the independent variable
B) The independent variables are introduced or manipulated, one at a time, by the researcher
C) There are one or more control groups that are not exposed to the independent variable.
D) Research participants are randomly assigned to experimental and control groups

Option c

Explanation:

In experimental design, there are lots of test to certify the essence of the design. When there exist an independent variable, every measure of control is applied to it to test if it measures the expectation ,so there can't be one or two control measure not applied to the independent variable, we have to test every respective attribute of the control measure, we have randomly apply different theories to see if the control measure with its independent variable meets standards that is why Option C is not a requirement

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).

the language of nature was a manifestation from god as he said "let there be light" and there was light the world began to assume visible, comprehensible form.

what ever we know now think of the old vision of creation we can be sure that with out the speaking of word -without language- we would have no science today with its striking power to illuminate the world.