Sharon,a Marketing Major,has Her First Economics Test and Her First

Multiple Choice

Sharon,a marketing major,has her first economics test and her first finance test to take tomorrow and she has four hours tonight to allocate to studying the two subjects.The data below show her scores on the two tests based on the time spent studying.(Hint: Studying economics for 0 hours means studying finance for 4 hours. )

-The sequence of marginal costs from the 1^st to the 4^th hour of economics studying is

A) 30,29,27,20.
B) 79,77,70,50.
C) 1,2,7,20.
D) -1,-2,-7,-20.
E) 1,3,10,30.