Answer:
The missing option in your statement is:
a. oil
During the Northern Renaissance, the use of oil painting was developed in Flanders. Oil painting allowed artists to achieve greater realism, depth, and detail in their artworks compared to other painting techniques of the time. Artists like Jan van Eyck and Rogier van der Weyden were pioneers in the use of oil paint, and their works exemplify the technical and aesthetic advancements made possible by this medium during the Northern Renaissance.
