Which is the largest Dome ?

Question

Which is the largest Dome ?

Answer 1

Golden Mosque, Islamabad,Pakistan.

Answer 2

O2, formerly the Millenium Dome, in London, United Kingdom, height: 365 m.

Answer 3

Gol gumbaz of bijapur

Answer 4

Both above answers are wrong, the largest dome is in London.  It is called the O2 and is 365 meters across.

Whereas the Gol Gumbaz is merely 38m and Golden Mosque doesn't even make the list.