What complication may occur as a result of improper venipuncture technique?

Improper venipuncture technique can lead to a variety of complications, and selecting "All of the above" captures this breadth of possible issues effectively.

Swelling may occur if blood leaks into the surrounding tissue, leading to a hematoma. This can happen when the needle is not positioned correctly within the vein, causing damage to the vessel wall.

Infection is another potential complication, especially if aseptic techniques are not followed during the procedure. Failure to properly clean the area or using contaminated equipment can introduce pathogens into the body.

Pain is often a result of improper technique as well. For instance, if the needle is inserted at an incorrect angle, or if the procedure is done without careful handling, the patient may experience more discomfort than necessary.

Overall, each of these complications – swelling, infection, and pain – is interrelated and can stem from poor venipuncture technique, making "All of the above" the most inclusive and accurate choice.