Explanation:

- Faulty Balance: The balance measures 25% less, so 1 kg according to the balance is actually 1.25 kg.

- Markup: The shopkeeper marks up the price by 15% above the cost price.

- Discount: He offers a 10% discount on the marked price.

- Actual Selling Weight: The customer pays for 1 kg, but gets 1.25 kg due to faulty balance.

Now, let's calculate:

1. Cost of 1 kg = $\text{Rs. 100 (Assumed)}$

2. Marked price for 1 kg = $100+15\mathrm{\%}\text{ of 100}=115$

3. Discounted price = $115-10\mathrm{\%}\text{ of 115}=103.50$

Net Profit Calculation:

- Customer Receives: 1.25 kg

- Cost for 1.25 kg = $1.25\times 100=125$

Profit = $103.50-125=-21.50$

Profit percentage = $\frac{-21.50}{125}\times 100=-17.2\mathrm{\%}$ (Loss), Remember this does not represent actual scenario.

There might be something on your calculations that provides other values when opting other way or narrative is misunderstood attributes, but correct analysis usually is:

Your answer seems off due typical assumptions regarding reasonable profit mechanism in pricing where estimation of net percent does not need further considerations. Option: 4 - 38% seems too high on provided scenario unless having different assumptions which cannot align directly with straightforward explanation of faulty scales and rest conditions.

Correct Approach provides ideal calculation requires right computations to proceed when fair traded kg is considered what ideally this specifics assumes potential market ups and intrinsic model based changes.