A machine that originally cost $10000$ was depreciated over two years at $10\%$ per annum by the straight-line method. It was later sold for cash, and the loss on disposal was $700$. On the same day, a replacement machine was purchased for $12400$ cash. What was the net decrease in the cash balance?
- A$3700$
- B$5100$
- C$11700$
- D$13100$