Why did the Ottomans attack Constantinople?

Fall of Constantinople, (May 29, 1453), conquest of Constantinople by Sultan Mehmed II of the Ottoman Empire. The dwindling Byzantine Empire came to an end when the Ottomans breached Constantinople’s ancient land wall after besieging the city for 55 days. Mehmed surrounded Constantinople from land and sea while employing cannon to maintain a constant barrage of the city’s formidable walls. The fall of the city removed what was once a powerful defense for Christian Europe against Muslim invasion, allowing for uninterrupted Ottoman expansion into eastern Europe.

what are the options ?

you didn't post any options. a few things that spring is known to represent are: rebirth, birth, new life,   and life.