Nikita bought $30 \text{ kg}$ of wheat at the rate of $Rs. 9.50$ per $\text{kg}$ and $40 \text{ kg}$ of wheat at the rate of $Rs. 8.50$ per $\text{kg}$ and mixed them. She sold the mixture at the rate of $Rs. 8.90$ per $\text{kg}$. Her total profit or loss in the transaction was:

• A
  $Rs. 2$ loss
• B
  $Rs. 2$ profit
• C
  $Rs. 7$ loss
• D
  $Rs. 7$ profit