mathematics - How much is the shopkeeper's loss?

A lady buys goods worth 200 rupees from the shopkeeper. The goods were reasonable quality merchandise sold for what the market would bear.

The lady gives the shopkeeper a 1000-rupee note. The shopkeeper runs out of change, and gets change from the next shop. He keeps the 200 rupees (for selling the goods) and returns 800 to the lady. Later the neighbour comes back with the 1000-rupee note, proving it's a fake, tearing it up and demanding his money back.

How much did the shopkeeper lose?

A) Rs. 200
B) Rs. 800
C) Rs. 1200
D) Rs. 1800
E) Rs. 1600
F) Rs. 2000
G) Other