In the following passage, some of the words have been left out. Read the passage carefully and select the correct answer for the given blank out of the four alternatives.
Immigration was exploited in the campaign with ______ cynicism, ______ by populist politicians from the lunar right, but by Labour politicians drawing on their own venerable tradition of promoting and nurturing racism, a symptom corruption not at the bottom but at the top. The reason millions of refugees ______ the Middle East ______ now Syria – are the invasions and imperial mayhem of Britain, the United States, France, the European Union and NATO.

______ by populist politicians from the lunar right, but by Labour politicians...

1. A
   not only
2. B
   although
3. C
   so
4. D
   as