The following sentence has been split into four segments. Identify the segment that contains a grammatical error.
Athens was / a most luminous / of all city-states / of ancient Greece.

Correct option is A

Option (a) contains a grammatical error.
Explanation of error:
· “ A most luminous” is incorrect usage.
· When comparing one among all, we use the superlative degree with ‘the’, not ‘a’.
· Correct usage is: “the most luminous”.
Corrected sentence:
Athens was the most luminous of all city-states of ancient Greece.
Grammatical rule used:
✔ Use ‘the’ before superlative adjectives like the best, the highest, the most luminous.
✔ Article “a” is used with singular countable nouns, not with superlatives.
Example:
· She is the most intelligent girl in the class. ✅
· ❌ She is a most intelligent girl of all. ❌
�� Grammar Booster:
�� Superlatives always require “the”. Only exception: poetic or old English uses.