please really need some help with work shown

Problem 2

A firm has $100 million in current liabilities, $200 million in total long-term liabilities, $300 million in stockholders' equity, and total assets of $600 million. Calculate the firm's ratio of long-term debt to long-term debt plus equity.

A. 30% B. 40% C. 20% D. 50% E. 17%