Which building is it?

----- Nội dung ảnh -----
Which building is it?
........ 1. This is the largest building in the world.
........ 2. This is the oldest building in the world.
........ 3. This is the tallest building in the world.
........ 4. This building has the fastest elevators.
........ 5. This building is made entirely of stone.
........ 6. This building is like a small city with many facilities.

Bên phải có hình ảnh của các công trình:
B - Knap of Howar
A - Burj Khalifa
C - Boeing Everett Factory