Correct option is A
Aluminium oxide (Al₂O₃) is considered the softest abrasive among the options provided. It is widely used in various grinding and sanding applications where less aggressive material removal is required.
- Diamond is the hardest known natural material, making it the hardest abrasive in this list.
- Silicon carbide (SiC) is also a very hard material, often used in industrial processes where extreme toughness is needed.
- CBN (Cubic Boron Nitride) is a synthetic material that is nearly as hard as diamond, making it another extremely hard abrasive.
In comparison to these, Al₂O₃ is softer, which makes it suitable for more delicate work where less aggressive material removal is needed, such as in the finishing and polishing of metals.
Hence, the correct answer is Al₂O₃.
