Please help! I'll give out brainliest.

Firms use marginal analysis to determine prices by a) changing prices in accordance with information from retailers. b) using comparisons with strong competitors to position prices accordingly. c) examining the effect on revenue of small changes to the price of one item. d) trying to minimize production costs by using better and more efficient methods.

Briefly explain how one development from the period 1861 to 1865 not directly mentioned un the excerpts supports mcpherson's argument

Arectangle is removed from a right triangle to create the shaded region shown below. find the area of the shaded region.be sure to include the correct unit in your answer.14 mmm² mxlal? 4m3m