Suppose we are fitting a model with Y = Income and X = Age. We are testing whether there is a U shaped effect by looking at how the R² changes when we incorporate Age * Age as an additional variable in our model. What will happen to the R²if there is not a statistically significant U shaped effect?

Group of answer choices

a. It might go up or down

b. It will stay the same or go down

c. It will stay the same or go up

d. It will go down