Final answer:
A pillar is an upright, relatively slender shaft or structure, usually made of brick or stone, used as a building support or standing alone as a monument.
Step-by-step explanation:
The correct answer is b) Pillar
A pillar is an upright, relatively slender shaft or structure, usually made of brick or stone, used as a building support or standing alone as a monument. Pillars can be found in various architectural styles throughout history.
One example of a pillar is the Colosseum in Rome, which uses repeated arches to define its structure.