Institution: জাতীয় কবি কাজী নজরুল ইসলাম বিশ্ববিদ্যালয় (JKKNIU) Exam: ক ইউনিট || জাতীয় কবি কাজী নজরুল ইসলাম বিশ্ববিদ্যালয় || 2012
Topic: বিবিধ, Subject: Bangla (বাংলা)

Best Answer Explained in Below-:

The phrase "আঠারো বছর বয়স পাথর বাঁধা ভাঙতে চায়" symbolizes the youthful desire and strength to break free from constraints (represented by "পাথর বাঁধা," or stone bindings). The options provided represent different means of breaking these bindings.

1. **হাত দিয়ে (by hand)** - This implies a gentle or less forceful approach, which may not convey the urgency or strength of the youthful desire to break free.

2. **হাতুড়ি দিয়ে (by hammer)** - While this suggests a stronger, more direct method, it too lacks the poetic resonance associated with youthful vigor and the inherent power of one's own body and spirit.

3. **চরণাঘাতে (by foot)** - This option symbolizes a more primal and powerful form of breaking away. Feet carry us forward, representing movement, progress, and the dance of life. It resonates with the idea of youthful energy and rebellion, as the foot can deliver strong, decisive blows, making it a metaphor for taking bold action and asserting independence.

4. **লগুড়াঘাতে (by log)** - This suggests a cumbersome means, possibly lacking the finesse or immediacy associated with youth.

Therefore, "চরণাঘাতে" is the most fitting choice as it encapsulates the raw vitality and determination of an eighteen-year-old eager to challenge limitations and assert freedom. This choice reflects a dynamic interaction between the individual and their environment, emphasizing the power of youth and the desire for liberation.