Answer:
a. The cash flows from investing activities section.
Step-by-step explanation:
The three types of cash flow activities are operating, financing and investing.
Operating activities include the operating income adjustments, depreciation and increases or decreases in current assets and liabilities.
Financing activities include proceeds from issue of bonds or stocks and interest paid or received.
Investing activities include purchase or sale of fixed assets and other investments.
The purchase of office building is an investing activity.
Hope that helps.