What are the seven methods of non-destructive evaluation (NDE)?

The correct choice includes methods such as visual inspection and magnetic particle inspection, which are two foundational techniques used in non-destructive evaluation (NDE). Visual inspection is a primary method that relies on the human eye or optical instruments to verify the integrity of materials, components, and structures. It's essential for identifying surface defects such as cracks, corrosion, and misalignment.

Magnetic particle inspection, on the other hand, is a technique used primarily for detecting surface and near-surface flaws in ferromagnetic materials. This method involves applying magnetic fields to a part and then dusting it with ferrous particles. When defects are present, the particles will gather at these locations, making them visible.

These techniques are critical because they allow engineers and technicians to assess the condition of materials and structures effectively without compromising their integrity. Other methods mentioned in the other selections, such as liquid penetrant or ultrasonic testing, are all important NDE techniques but do not encompass the full variety of methods mentioned in the correct choice. This ensures a comprehensive understanding of different evaluation methodologies within NDE practices.