This is a test of commonsense with single/multi-choices. Complete the next sentence:

How to clean a clogged drip system
Flush a clogged emitter.
Turn on your drip irrigation system. Hold your finger over the clogged emitter's outlet for a few seconds and let the water flush back to clean the emitter.

pick from the following. (1). The water should clear away both the drip and the pour away components. Use a standalone hose or irrigation system.. (2). Take the vinegar out of the water after a few moments. Use a low-stress cleaning solution.. (3). Open the emitter and manually clean it if necessary. Check if your irrigation model requires this.. (4). This prevents water from splashing and decreases the length of drip irrigation. Run the drip irrigation system through one filter of the drip irrigation system and clear out any lingering debris..
The answer is:
(3).