Explanation:

- The word "impeccable" describes something flawless or without any defects.

- Option 1: Faultless

- Meaning is very similar to impeccable; it also indicates something without fault or error.

- Option 2: Unsullied

- This means not spoiled or made impure, carrying a sense of purity. It aligns with "impeccable."

- Option 3: Imperfect

- This means not perfect and is the opposite of impeccable. It indicates the presence of flaws or defects.

- Option 4: Methodical

- Describes something done in an orderly, systematic way. It doesn't directly relate to perfection or flaws.