The holy trinity fresco, by masaccio, is considered to be the first painting based on the systematic use of:

The correct answer is linear perspective

This is the artistic idea that all points in a painting should converge into a single point that is somewhere far away in the background. This is great for giving the impression of three dimensional space. Nowadays, it's quite common and is learned very quickly in drawing schools, but at the time it was revolutionary.

Iwould have to say c. the german americans.