Final answer:
The Erechtheion uses the Ionic order, which is distinguishable by its slender, elegant columns with scroll-like capitals and a base.
Step-by-step explanation:
The Erechtheion, an ancient Greek temple on the Acropolis of Athens, is primarily known for its use of the Ionic order. The Ionian architectural order can be recognized by its slender, elegant proportions and scroll-like ornaments (volutes) on the capital, which contrast the simpler and sturdier design of the Doric order.
Furthermore, Ionic columns characteristically stand on a base, unlike the Doric columns that sit directly on the stylobate. The Erechtheion is a significant example of the Ionic style, particularly famous for its Caryatid Porch where instead of Ionic columns, sculpted female figures serve as the supportive elements.