Change into comparative degree: 'Very few cities in the world are as big as Dhaka.'

1. ক
   Dhaka is bigger than most other cities in the world.
   
2. খ
   Dhaka is the biggest city in the world.
   
3. গ
   Dhaka is as big as other cities in the world.
   
4. ঘ
   Dhaka is bigger than any other city in the world.