Below is a graphical display of a sensitivity analysis showing the project NPV that results from changes to the base case of input variables. NPV is most sensitive to changes in which of the input variables?

a. the variable represented by the red line

b. the variable represented by the blue line

c. the variable represented by the green line

d. the variable represented by the thin black line

NPV ($000s) 400 300 200 100 -100 % Change from Base Case -30 -20 -10 Base +10 +20 +30 0 Case