The balance sheet and income statement shown below are for Zanobia Inc. Note that the firm has no amortization charges, it does not lease any assets, none of its debt must be retired during the next 5 years, and the notes payable will be rolled over. Refer to Exhibit above. What is the firm's operatung margin: Do not round your meruscusav calculations. Select one: a. 4.23% b. 4.32% c. 5.80% d. 4.75% e. 3.80%