Johnson & Johnson presented an income statement for the year ended December 31, 2023, showing sales of $103,484 million and cost of sales of $34,709 million, resulting in a gross profit of $68,775 million. Operating expenses were $42,381 million, leading to an operating income of $26,394 million. After accounting for interest expenses of $1,083 million and income taxes of $5,612 million, Johnson & Johnson reported a net income of $19,699 million.

a. Compute Johnson & Johnson's gross profit margin. b. Determine the operating income margin for Johnson & Johnson. c. Discuss the impact of Johnson & Johnson's operating expenses on its profitability. d. Analyze the net income trend for Johnson & Johnson over recent fiscal periods.