The answer is 3) Great Britain did not have the resources to maintain an empire after World War II
Even though Britain was able to defeat Germany and the Axis powers in Europe, overall the Empire was in socioeconomic shambles.
The war had resulted in the destruction of hundreds of businesses and factories. London itself was bombarded and the many government officials operated from bunkers.
Millions of men had died and there was a lack of resources.
The government could do things, use the remaining reserves to either rebuild Great Britain or maintain the large Empire. At the end it was decided to give away the Empire and work on rebuilding Britain