Hawk Company paid $500,000 for Diamond Company bonds in 2019 and classified the investment as available for sale. The market value of the Diamond Company bonds was $600,000 on 12/31/19, and $650,000 on 12/31/20. During 2021, Hawk sold all of its Diamond Company bonds for $700,000. In its 2021 income statement, Hawk would report: A. A gain of $300,000. B. A gain of $50,000. C. A gain of $150,000. D. A gain of $200,000.