Final answer:
The subject of the question is the medium used in the painting 'Madonna and Child with the Chancellor Rolin' by Jan van Eyck, which is c. oil painting.
Step-by-step explanation:
The subject of your question is art, specifically the medium used in the painting 'Madonna and Child with the Chancellor Rolin' by Jan van Eyck. The painting is an c. oil painting, not a fresco, tempera, or encaustic painting.
Van Eyck was an early inventor of oil painting and used this technique in many of his works. 'Madonna and Child with the Chancellor Rolin' is located in the Louvre and was created around 1433-1434.