Education is enlightening. Here ‘enlightening’ is—

✅ কেন সঠিক: ‘Enlightening’ describes the subject ‘Education’ after the linking verb ‘is’. A verb + -ing used as an adjective is a present participle.

❌ অন্য অপশন: A gerund works as a noun, an infinitive has ‘to’, and a finite verb shows tense — ‘is’ is the finite verb here, not ‘enlightening’.

💡 মনে রাখুন: -ing as adjective = participle; -ing as noun = gerund.

📖 শব্দার্থ: enlightening = জ্ঞানদায়ী, আলোকিত করে এমন; অর্থ: শিক্ষা আলোকিত করে।