Let cost price of article be Rs.100\(x\)
Marked price = Rs.130\(x\)
After 20% discount, selling price =\(\frac{80}{100}\times\) 130\(x\)=208
4 ×26\(x\)=208
\(x=2\)----(i)
Thus, cost price of article = Rs. 200
Therefore, Net profit as percent of cost price =\((\frac{SP-CP}{CP})\times100\)
=\((\frac{208-200}{200})\times100=4\%\)
The correct answer is (B): 4%