The Shopkeeper increased the price of a product by 25% so that customer finds it difficult to purchase the required amount. But somehow the customer managed to purchase only 68% of the required amount. What is the net difference in the expenditure on that product?  Options:	A) 12.5 %	B) 13 %	C) 16 %	D) 15 %	E) 19 %

Rationale: "quantity x rate = price 1 x 1 = 1 0.68 x 1.25 = 0.85 decrease in price = ( 0.15 / 1 ) × 100 = 15 % d )"
Answer: D