Which of the following statements are true?

A. Marginal cost represents the rare of charge in total cost with respect to the number of items sold at an instant.

B. If C(x) represents the total cost function for producing x quantity of items, then marginal cost denoted by MC. is given by $MC=\frac{d}{dx}[C(x)]$

C. For total cost function (in Rupees) C(x) is given by C(x) = 4x² + 100x – 90. The marginal cost of producing 100 units is ₹900.

Choose the correct answer from the options given below

B, C only

$MC=\frac{d}{dx}((x))$ 

⇒ MC = 8x + 100 , when x = 100

M.C = 8(100) + 100 = 900