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

How to bend pipe 
Choose the right bending tools for your needs. 
There are 6 main bending methods. Each is best suited to a particular type of pipe.

Select from:
 1). At least 4 of the more standard gauges and fittings have curved pipe joints. For some types of pipes, then they might be appropriate to a particular type of pipe.
 2). There are simpler and more durable methods, but basic (preferably quicker and more expensive) tools are good for applying proper conditioning, shifting, changing the electric potentiometer, shooting, and modifying or tightening various varieties of pipes. To perform them properly, see these guide at how to learn the proper line-shift, piece theory, or in a new recipe.
 3). Ram style bending, also called incremental bending, is usually used for putting large bends in light-gauge metal, such as electrical conduit. In this method, the pipe is held down at 2 external points and the ram pushes on the pipe at its central axis to bend it.
 4). Both methods are ideal for straight pipe pipe. Straight pipe pipe allows for control over exactly how you bend the pipe into the exact position.
The answer is:
3).