synecdoche
Hi, I wasn't saying D is correct instead of E. When I saw it, I couldn't decide what to answer. You're correct about the "employee illness prevention", but in E, shouldn't it be "through improved worker performance by simply providing offices" instead of "through improved worker performance if they simply provided offices" as that'd be parallel to "by preventing illness....". That's the part I'm not sure about.
Hi,
If you read Choice E carefully, you will see that the two entities that are parallel are:
a. could save as much as $58 billion by preventing illness among employees
b. could gain as much as $200 billion through improved worker performance
If you carefully analyze these two entities, you will see that the first part till “billion” are absolutely parallel to each other and there is no confusion about that. Now, what should be parallel to “by preventing illness among employees” is “through improved worker performance”. Why? It is because the companies could save “by” preventing illness among employees, and the companies could gain “through” improved worker performance. The ways how companies could save and gain have been written in prepositional phrases beginning with “by” and “through” respectively.
Structurally again “verb-ing modifier” preventing illness among employees” and verb-ed modifier “improved worker performance” are parallel.
The important thing is to identify the correct parallel list. Now the gains could not be made by providing offices with cleaner air. This is a condition.
If the companies provided offices with cleaner air, then they could do things (these need to be parallel):
a. could save as much as $58 billion by preventing illness among employees
b. could gain as much as $200 billion through improved worker performance
Cleaner air could not just help the companies gain by doing something but also help them save by doing something. Both these things could be the outcome if the companies provided the offices with cleaner air. Hence, the two outcomes should be parallel. By making “by preventing…” and “by providing…”, we will make the condition parallel to just one of the outcomes, and this is not logical per the context of the sentence.
Hence, make sure to identify the correct list in the sentence to ensure correct parallelism.
Hope this helps.
Shraddha