DEF Enterprises, a technology firm, presents its balance sheet as of December 31, 2023. The company's assets include cash, accounts receivable, investments, intangible assets, and property. Liabilities consist of accounts payable, accrued liabilities, and long-term debt. Shareholders' equity comprises common stock, preferred stock, and retained earnings. DEF Enterprises' balance sheet reflects its recent investment in research and development. Requirements: a. Calculate the total assets of DEF Enterprises. b. Determine the total liabilities. c. Analyze the impact of R&D investment on shareholders' equity.