Reading is an excellent habit. Here, the underlined word (Reading) is a—

✅ কেন সঠিক: ‘Reading’ is the subject of the sentence and works as a noun, so it is a gerund (verb + -ing used as a noun).

❌ অন্য অপশন: A participle works as an adjective; a verbal noun usually takes ‘the’ and ‘of’ (the reading of books); ‘reading’ is not a finite verb here.

💡 মনে রাখুন: -ing as subject/object = gerund.

📖 শব্দার্থ: অর্থ: পড়া একটি চমৎকার অভ্যাস।