Answer the following question given this paragraph: 

Nitrogen Oxyacids and Salts Nitrogen pentaoxide, N2O5, and NO2 react with water to form nitric acid, HNO3. Alchemists, as early as the eighth century, knew nitric acid (shown in Figure 18.50) as aqua fortis (meaning "strong water"). The acid was useful in the separation of gold from silver because it dissolves silver but not gold. Traces of nitric acid occur in the atmosphere after thunderstorms, and its salts are widely distributed in nature. There are tremendous deposits of Chile saltpeter,.


Q: Alchemists, as early as the eighth century, knew nitric acid as aqua fortis, which means?

 Choices:

- isolated water

- clean water

- applied water

- strong water

A:
strong water
