Explanation
এখানে সঠিক উত্তর হল- D) Assiduous. Diligent অর্থ অধ্যবসায়, ক্রিয়াশীল, পরিশ্রমী, অনলস, সযত্ন, ক্রিয়াপর, নিরলস। Assiduous হল Diligent একটি synonym. Option A, "Lethargic," means lacking in energy or enthusiasm, and is an antonym of diligent, not a synonym. Option B, "Weak," means lacking in strength, and does not have the same meaning as diligent. Option C, "Dull," means lacking interest or excitement, and is not a synonym of diligent.