Merrimac Brewing company's total assets equal $18 million. The book value of Merrimac's equity is $6 million. The market value of Merrimac's equity is $10 million. It's Debt to Value ratio is .5. What is the book value of Merrimac's interest- bearing debt?
A) $5 million
B) $10 million
C) $15 million
D) $20 million