The balance sheet and income statement shown below are for Koski 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.

Balance Sheet (Millions of $)

Assets 2018

Cash and securities $3,000

Accounts receivable 15,000

Inventories 18,000

Total current assets $36,000

Net plant and equipment $24,000

Total assets $60,000

Liabilities and Equity Accounts payable $18,630

Accruals 8,370

Notes payable 6,000

Total current liabilities $33,000

Long-term bonds $9,000

Total liabilities $42,000

Common stock $5,040

Retained earnings 12,960

Total common equity $18,000

Total liabilities and equity $60,000

Income Statement (Millions of $) 2018

Net sales $84,000

Operating costs except depreciation 78,120

Depreciation 1,680

Earnings before interest and taxes (EBIT) $4,200

Less interest 900

Earnings before taxes (EBT) $3,300

Taxes 1,320

Net income $1,980

Other data: Shares outstanding (millions) 500.00

Common dividends (millions of $) $693.00

Int rate on notes payable & L-T bonds 6%

Federal plus state income tax rate 40%

Year-end stock price $47.52

Refer to Exhibit 4.1.

What is the firm's return on invested capital? a. 8.32% b. 6.41% c. 6.03% d. 8.63% e. 7.64%