Answer:
D. -4
Step-by-step explanation:
The formula for calculating the slope of his indifference curve at his current consumption is expressed as:
M = -∆y/∆x
∆y is the change in y axis
∆x is the change in x axis
Since apples are put in the horizontal axis, ∆x = 20
Since banana are on the y axis, then ∆y = 80
Substituting the given values into the formula
M = -80/20
M = -8/2
M = -4
Hence the slope of his indifference curve at his current consumption is -4.
Option D is correct.