Although a few years ago the fundamental fact about the Milky Way seemed fairly well —, now even its mass and radius have come into —.

✅ কেন সঠিক: ‘Although’ signals a contrast: the facts once seemed well established, but now even basic values have come into question (are doubted).

❌ অন্য অপশন: ‘Come into resolution’, ‘come into danger’ and ‘diminished… disrepute’ do not form the natural contrast or idiom.

💡 মনে রাখুন: Look for the clue word: although / but / yet = contrast. ‘Come into question’ is a fixed phrase meaning ‘become doubtful’.