When seven variables are fitted into a regression model, only three are significant. Which one of the following is the correct next step?
Select one:
a. Refit the model without the significant variables.
b. Refit the model without the non-significant variables.
c. There is no need to refit the model, as the model equation includes only the significant variables.
d. Refit the regression without the variable with the largest p-value.