Correct answer is: b) 4

Explanation

Let,
The number is ‘100’.
If it increased by 30%, then the number will be :
\{100+\left(100\times\frac{30}{100}\right)\}
\rightarrow\left(100+30\right)
\rightarrow 130
Now, After increased the number it reduced again 20%.
So that, after reducing the number will be :
\{130+\left(130\times\frac{20}{100}\right)\}
\rightarrow\left(100-26\right)
\rightarrow 104
\therefore The total change that occurs to the original number is \left(104-100\right)
\rightarrow 4
Ans: The total change is 4.