Marginal analysis is very important in business and economics. In the following example below, a company manufactures fuel tanks for cars. The total weekly cost in dollars of producingxtanks is given by

C(x) = 10,000 + 90x - 0.05x²

Explain how you would:

(A) Find the marginal cost function.

(B) Find the marginal cost at a production level of 400 tanks per week.

(C) Interpret the results of part (B).

(D) Find the exact cost of producing the 401st item.

please show work when providing an explanation of the answer(s).