Final answer:
Derick should click on the 'Data' function to insert subtotals for grouping income and expenses in a spreadsheet. Therefore correct option is D
Step-by-step explanation:
If Derick wants to insert subtotals into his spreadsheet after selecting the necessary cells, the first function he should click on is Data. In many spreadsheet applications, the subtotal function is located under the Data menu. This allows users to perform functions like grouping and summarizing data. In this case, Derick would use it to create groups for his firm's income and expenses, allowing for a better-organized income statement.