An example of cash flow from investing activity is :

Sale of investment by non-financial enterprise

The correct answer is option 3- Sale of investment by non-financial enterprise.

As per AS-3, investing activities are the acquisition and disposal of long-term assets and other investments not included in cash equivalents. Investing activities relate to purchase and sale of long-term assets or fixed assets such as machinery, furniture, land and building, etc. Transactions related to long-term investment are also investing activities. So, sale of investment by non financial enterprise is an investing activity.

* Issue of debentures for cash and repayment of long term loans are financing activity.