Annual savings

[zaarathelab]

Each year companies in the United States could save as much as $58 billion annually by preventing illness among employees and gain as much as $200 billion through improving performance of workers if they simply provided offices with cleaner air.
(A) annually by preventing illness among employees and gain as much as $200 billion through improving performance of workers if they simply provided
(B) annually if they prevented employee illness and gain as much as $200 billion through worker performance improved by simply providing
(C) annually in employee illness prevention and gain as much as $200 billion through worker performance improved by simply providing
(D) in employee illness prevention and gain as much as $200 billion through improving performance of workers if they simply provided
(E) by preventing illness among employees and gain as much as $200 billion through improved worker performance if they simply provided

[spoiler]OA is E. why not D?[/spoiler]

[GmatKiss]

Each year companies in the United States could save as much as $58 billion annually by preventing illness among employees and gain as much as $200 billion through improving performance of workers if they simply provided offices with cleaner air.
(A) annually by preventing illness among employees and gain as much as $200 billion through improving performance of workers if they simply provided
(B) annually if they prevented employee illness and gain as much as $200 billion through worker performance improved by simply providing
(C) annually in employee illness prevention and gain as much as $200 billion through worker performance improved by simply providing
(D) in employee illness prevention and gain as much as $200 billion through improving performance of workers if they simply provided
(E) by preventing illness among employees and gain as much as $200 billion through improved worker performance if they simply provided

[spoiler]OA is E. why not D?[/spoiler]

"employee illness prevention" is inferior to "preventing illness among employees"
also
"improved worker performance" is superior to "improving performance of workers "

WORKERS is wrong in D ( it has to be EMPLOYEES)

IMO: D seems passive

Hope it helps

[avik.ch]

Each year companies in the United States could save as much as $58 billion annually by preventing illness among employees and gain as much as $200 billion through improving performance of workers if they simply provided offices with cleaner air.
(A) annually by preventing illness among employees and gain as much as $200 billion through improving performance of workers if they simply provided
(B) annually if they prevented employee illness and gain as much as $200 billion through worker performance improved by simply providing
(C) annually in employee illness prevention and gain as much as $200 billion through worker performance improved by simply providing
(D) in employee illness prevention and gain as much as $200 billion through improving performance of workers if they simply provided
(E) by preventing illness among employees and gain as much as $200 billion through improved worker performance if they simply provided

[spoiler]OA is E. why not D?[/spoiler]

The major difference between D and E is the difference between "in" and "by".

Please consider these two example :
I invested more than 1000$ in XXXXXXXXXX ( where I invested the amount )
I invested more than 1000$ by decreasing my spending rate............( its a action taken in order to invest )
As far as meaning is concerned of the original sentence "by" is apt. Now I hope you got why E is right.

I hope this helps.

[aspirant2011]

Each year companies in the United States could save as much as $58 billion annually by preventing illness among employees and gain as much as $200 billion through improving performance of workers if they simply provided offices with cleaner air.
(A) annually by preventing illness among employees and gain as much as $200 billion through improving performance of workers if they simply provided
(B) annually if they prevented employee illness and gain as much as $200 billion through worker performance improved by simply providing
(C) annually in employee illness prevention and gain as much as $200 billion through worker performance improved by simply providing
(D) in employee illness prevention and gain as much as $200 billion through improving performance of workers if they simply provided
(E) by preventing illness among employees and gain as much as $200 billion through improved worker performance if they simply provided

[spoiler]OA is E. why not D?[/spoiler]

[saketk]

we need 'provided' instead of 'providing' also if you look at the meaning of the sentence the author wanted to say that - companies could save $$$ by doing a certain thing ( in this case 'preventing illness among employees')

He is suggesting an action for the expected result.