Los Angeles freeways

[gmat009]

In the mid-1970’s, since birds were overcome by pollution, and routinely falling from the sky above Los Angeles freeways, this prompted officials in California to devise a plan that reduced automobile emissions.
A. since birds were overcome by pollution, and routinely falling from the sky above Los Angeles freeways, this prompted officials in California to devise a plan that reduced
B. since birds that had been overcome by pollution were routinely falling from the sky above Los Angeles freeways, it prompted officials in California to devise a plan that would reduce
C. birds had been overcome by pollution and routinely fell from the sky above Los Angeles freeways, prompting officials in California to devise a plan that reduced
D. birds overcome by pollution routinely fell from the sky above Los Angeles freeways, prompting officials in California to devise a plan to reduce
E. birds overcome by pollution and routinely falling from the sky above Los Angeles freeways were prompting officials in California to devise a plan to reduce

Confused between D & E. Which one is better and why......

[lalitgmat]

A & B are OUT because they are WORDY.
C is VERB/Tense mismatch.
E is violating Cause-Effect Relationship. Officials were NOT taking action as and wehn birds were falling.
I click "D". what is OA ?

[chase4meg]

D for me too...

"routinely falling from sky" is awkward..

[rohangupta83]

'D' for me too. Rest of them are awkward constructions and long. 'D' for me is clear and concise.

[tallynik]

D for me too.
Just seems short and all tenses match.

Definitely not E. The action of routinely falling birds prompted officials to respond, not the birds in itself. Were prompting modifies birds hence incorrect.

[raajan_p]

The answer is D..

Two things to note between D and E

E states that "birds overcome by pollution and routinely falling from the sky above Los Angeles freeways were prompting officials in California to devise a plan to reduce
"

usage of "and" is incorrect here.
E incorrectly refers that birds prompt officials in california to devise a plan.

On the other hand D tells that the fact ("birds overcome by pollution fell from the sky above los angeles freeways") prompted officials in california to devise a plan

[logitech]

So what iare the Subject and VERB in this sentence and what is the tense used ?

[raunekk]

imo:D

[andy9590]

"D", as it is standing out the most among the other options.

[NSNguyen]

IMO: D