A bank currently has $50 million in stable deposits against which they want to keep 10% reserves, $100 in vulnerable deposits against which they want to keep 40% reserves, and they have $50 million in "hot money" deposits against which they want to keep 90% reserves. The legal reserves for this bank are 10% of all deposits. What is the bank's liability liquidity reserve? A. $90 million B. $81 million C. $70 million D. $20 million E. None of the options is correct

how is the answer B how do we solve it?