2009 pp2 mc 5

Consider the fomula of calculating the multiplier(k),
　　　 　 1
k = (--------------------)
　 　 1-c-d+ct+m

You can substitude random numbers into it.
(larger than 0 and smaller than 1)

A --- d falls --- k rises
B --- s falls --- c rises --- k falls
C --- m falls --- k rises
D --- t falls --- k rises

you will finally find out the answer is B