Step 1: Context.
In Mahadevi Verma's story *Gillu*, the small squirrel finds ways to survive harsh conditions. Gillu discovered a new method to tackle winter cold.
Step 2: Option analysis.
(A) winter cold: Correct.
(B) summer heat: Incorrect.
(C) rainy season: Incorrect.
(D) strong winds: Incorrect.
Step 3: Conclusion.
Correct answer is (A) winter cold.