A. the half note
The current count in the second measure is one (two) and. To achieve a complete four counts, a half note is necessary to fulfill the remaining beats 3 and 4.
B. The application of oil paints allows for the depiction of highly realistic details. The Northern International style is noted for its emphasis on symbolism and intricate detail in objects. Their main focus was accuracy and meticulous detail; this Gothic Style of Medieval art primarily featured religious imagery, eventually transitioning into the Early Renaissance style of painting and sculpture.