Explanation:

- Cost Price (CP): The original price of the article.

- Marked Price: This is set at 30% above the cost price. So, if CP is $100$, Marked Price is $130$.

- Discount: A 20% discount is given on the Marked Price. So, selling price is calculated as $130-(20\mathrm{\%}\text{ of }130)=130-26=104$.

- Selling Price (SP): After discount, selling price is $104$.

- Profit: The difference between the Selling Price and Cost Price. $104-100=4$.

- Profit Percentage: Calculated as $\frac{4}{100}\times 100\mathrm{\%}=4\mathrm{\%}$.

- Option 1: 4% - This is the correct answer as calculated above.

- Option 2: 9% - Is incorrect as it overestimates the profit.

- Option 3: 6% - Is incorrect as well.

- Option 4: 5% - This represents an overestimation of profit.

Based on the explanation: