Step 1: Identify the key characteristics: it's an intaglio technique, acid is not used, and light (U.V.) and water are involved.
Step 2: Assess the choices. This modern, non-toxic printmaking method is called Solarplate printing. It uses a steel plate covered with a light-sensitive polymer. An image transparency is put on the plate and exposed to UV light (from sunlight or a light unit). The plate is then "developed" with water, removing the unexposed polymer to create an intaglio plate that can be inked and printed like a standard etching, but without harmful acids.