Question

What innovative and extreme lighting technique did Italian Baroque artist Caravaggio use in his paintings?

Answer 1

Yep, your guess is right! Tenebrism, is the correct answer!
"Tenebrism deals with the extreme contrast of light and dark, along with chiaroscuro, the two effects were what Caravaggio used to make his paintings seem so dramatic."
 
Or maybe I'm wrong xD. Hopefully I helped!