Which of the Following Are Often Considered Disadvantages of the Use

Multiple Choice

Which of the following are often considered disadvantages of the use of adjusted R² as a variable addition / variable deletion rule?
(I) Adjusted R² always rises as more variables are added
(ii) Adjusted R² often leads to large models with many marginally significant or marginally insignificant variables
(iii) Adjusted R² cannot be compared for models with different explanatory variables
(iv) Adjusted R² cannot be compared for models with different explained variables.

A) (ii) and (iv) only
B) (i) and (iii) only
C) (i) , (ii) , and (iii) only
D) (i) , (ii) , (iii) , and (iv) .