Some toffees are bought at the rate of 11 for Rs. 10 and the same number of toffees are bought again at the rate of 5 for Rs. 6, If the whole lot is sold at one rupee per toffee, then the gain/loss percent, correct to one decimal place, on the whole transaction is:

• A. 5.2% loss
• B. 5.2% gain
• C. 5.5% loss
• D. 5.5% gain