What painting technique describes the style of Caravaggio?

a$.)$

Shading using gradations of values and strong contrasts of light and dark to create a sense of volume

b$.)$

Creating large areas of dark colors that are illuminated by a single light source

c$.)$

Creating an optical illusion, usually of a three$-$dimensional space on a flat surface

d$.)$

Blending subtle tones into one another without harsh outlines, creating a "smoky" appearance