Calculate the operating risk ratio for a bank with the following characteristics ($Mils): Interest Revenue Interest Expense Net Interest Margin Non-Interest Income Non-interest Expense Income Before Taxes Provision for Taxes Net Income Total Avg. Assets Total Avg. Liabilities Total Avg. Bank Equity $105 $25 $80 $40 $75 $45 $15 $30 $300 $250 $50 O a. The Operating risk ratio is 62.4% b. The Operating risk ratio is 43.8% c. The Operating risk ratio is 33.3% d. The Operating Risk ratio is 93.8%