Final answer:
The triptych is most closely associated with the International Gothic style, known for its panel paintings and intricate works of art.
Step-by-step explanation:
The triptych is a type of artwork most closely associated with the International Gothic style. While Ancient Egyptian art is known for its considerable sophistication in painting and sculpture, and Abstract Expressionism is noted for its dominant influence in the 20th century, triptychs were not a common format in these styles. International Gothic art, known for its detailed panel paintings, stained glass, and other forms, indeed used the triptych format, which typically featured central and side panels that could be closed like a book.