What precautions are necessary when placing a ladder against a building on a sidewalk? select one: a. barricade the area or position a worker in front of the ladder. b. only use scaffolding when working where pedestrians might be walking. c. shut down the sidewalk in front of the building and direct pedestrians to the other side of the street. d. there are no special precautions necessary.

a. Barricade the area or position a worker in front of the ladder.

Explanation:

When one is using a ladder which has to be placed against the building on the sidewalk, the precaution used must be (from the four options) :-

a. Barricade the area or position a worker in front of the ladder.

This is because the area in which the worker is putting the latter is the prone are where the worker or the ladder might hit the pedestrian or any thing which can cause harm to the nature and mankind and that's why, the area must be blocked or defended with an improvised barrier.

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).

answer; the three types of research;