Select the most appropriate option to fill in the blank.
Most of the students in the first year were unable to score good marks due to their __________ nature.

Correct option is C

The correct option to fill in the blank is (c) nonchalant.
Nonchalant means casual, indifferent, or lacking concern, which fits logically as the reason students failed to score well. (लापरवाह)
Example: His nonchalant attitude cost him the job.
Meanings of all the options:
· (a) Deliberate – done intentionally (जानबूझकर किया गया)
· (b) Enthusiastic – showing intense interest or eagerness (उत्साही)
· (c) Nonchalant – not showing concern or enthusiasm (लापरवाह) ✅
· (d) Concerned – worried or thoughtful (चिंतित)