When increased demand for urban services combines with a shrinking tax base (where businesses and affluent people move out to the suburbs and beyond), central cities around the country struggle with
a. the fiscal squeeze.
b. urban sprawl.
c. invasion and succession.
d. isotopic surfaces.
e. how to fill ecological niches.

The correct option is A: the fiscal squeeze

Explanation:

When there is an increase in the demand of urban services but there is a shrink in the tax base, a situation where people move out from urban areas to rural and suburbs, there is every tendencies that the country will have a huge struggle with the fiscal squeeze. This is because the government will try to increase the taxes and hard revenue squeezes.

They struggle with a. fiscal squeeze.

Explanation:

Fiscal squeeze is experienced when income reduces over time and expenses continue to increase, which cause the body in question to experience problems in meeting its budgetary requirements.

In the case of central cities, a shrinking tax base is a reduction in income as public entities derive their incomes from taxes. Likewise, an increase in the demand of urban services increase their budgetary requirements as it is incumbent upon them to provide these services. When both of these stimuli are introduced, they experience a fiscal squeeze.

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).