A student was asked to calculate the surface area of a cube. 
He calculated the volume. 
The reason (s) of error in calculation is/are- 
I. the student finds the class boring as he does not like mathematics class 
II. the student is not fit to study in that class 
III. the student is not able to understand the concept of surface area and volume 
IV. the student has understood the concept of surface area and volume 
Select the correct answer using the code given below.