I don't think this has been posted before:

Unlike the United States, where farmers can usually depend on rain or snow all year long, the rains in most parts of Sri Lanka are concentrated in the monsoon months, June to September, and the skies are generally clear for the rest of the year.

A)
B) Unlike the United States farmers who can usually depend on rain or snow all year long, the rains in most parts of Sri Lanka
C) Unlike those of the United States, where farmers can usually depend on rain or snow all year long, most parts of Sri Lanka's rains
D) In comparison with the United States, whose farmers can usually depend on rain or snow all year long, the rains in most parts of Sri Lanka
E) In the United States, farmers can usually depend on rain or snow all year long, but in most parts of Sri Lanka the rains

OA [spoiler]E, can someone please explain why 'but' is used and an example of what the correct sentence would be by using "unlike"[/spoiler]

Thank you!

Jason