58. NVIDIA Corporation had the following financial data for the year ending January 31, 2023:
59. 
    
    • Total Assets: $200 billion
    • Total Liabilities: $50 billion
    • Shareholders' Equity: $150 billion

a) Calculate the debt-to-equity ratio. b) Determine the return on assets (ROA), assuming the net income for the year is $20 billion. c) Compute the return on equity (ROE), assuming the net income for the year is $20 billion.