Microsoft Corporation presented the following income statement details for the year ended June 30, 2023:

Item	Amount (in millions)
Revenue	$168,088
Cost of Revenue	$50,422
Gross Profit	$117,666
Operating Expenses	$61,792
Operating Income	$55,874
Interest Expense	$545
Income Before Taxes	$56,077
Income Tax Expense	$14,135
Net Income	$41,942

a. Calculate Microsoft Corporation's gross profit margin. b. Determine the operating income margin for Microsoft Corporation. c. Discuss the impact of Microsoft Corporation's interest expense on its profitability. d. Analyze the effective tax rate of Microsoft Corporation and its implications.