Austenitic stainless steels are paramagnetic; this means that:

Alternating current must be used when applying the magnetic particle testing method.

The steel is very dense and, relative to other steels, difficult to penetrate with X-rays.

Ultrasonics is the logical NDT method to choose because of the coarse-grained nature of a paramagnetic material.

All of the above are true.

None of the above is true.