ব্যাখ্যা
This question tests understanding of the word class of "leisurely," which can confuse students due to the "-ly" suffix.
Common Misconception:
Most words ending in "-ly" are adverbs (quickly, slowly, happily). However, "leisurely" is an EXCEPTION.
Why "leisurely" is an Adjective here:
"After lunch we went for a leisurely stroll"
— "leisurely" is placed before "stroll" (a noun)
— It modifies the noun "stroll"
— Adjectives modify nouns
→ Therefore, "leisurely" is an ADJECTIVE here
Derivation:
Leisure (noun) + -ly = Leisurely (adjective)
This follows the pattern:
— Friend → Friendly (adjective)
— Love → Lovely (adjective)
— Cost → Costly (adjective)
— Time → Timely (adjective)
"Leisurely" as Adverb (different context):
— "She walked leisurely." — Here it modifies the verb "walked" → adverb
So "leisurely" can be BOTH adjective and adverb depending on usage. In this sentence it modifies the noun "stroll" → adjective.
Source: Oxford Advanced Learner's Dictionary; Longman Grammar of Spoken and Written English.