The Soviets thought that the Marshall Plan, the United

E for me .... seems parallel to me .... prepositions to prepositions...

Whats OA

Seems B

Soviets thought that Plan, the U.S's
blueprint for blah blah in Europe ------> 1
as well as
subtle strategy to install blah blah---->2
, represent an blah blah

1 is parallel with 2

daagh, I am sure you wanted to convey something that I didn't get. I see it like this:

B) as well as a subtle strategy to install capitalism and repel communism, represented

The Soviets thought that the Marshall Plan, the United States’
blueprint for
>>>>>>>>>aiding AND
>>>>>>>>>rebuilding war-torn countries in Europe

AS WELL AS

a subtle strategy to
>>>>>>>>>install capitalism AND
>>>>>>>>>repel communism
,represented an insidious effort to implement the Truman Doctrine.

This is making complete sense and is parallel too.

E) and in installing capitalism and repelling communism a subtle strategy too, represented

The Soviets thought that the Marshall Plan, the United States’ blueprint:
for aiding and rebuilding war-torn countries in Europe AND
in installing capitalism and repelling communism a subtle strategy too, represented
an insidious effort to implement the Truman Doctrine.

Here, blueprint seem to have achieved both the tasks:
blueprint:
for aiding
AND
in installed capitalism

Now, blueprint for something makes sense.
blueprint in something doesn't.

Ans: "B"
*******************************

@ fluke
I said E is convoluted somewhat, so let me straighten it a bit. Read with the other parts,
Original E): The Soviets thought that the Marshall Plan, the United States’ blueprint for aiding and rebuilding war-torn countries in Europe and in installing capitalism and repelling communism a subtle strategy too, represented an insidious effort to implement the Truman Doctrine
Flipped: The Soviets thought that the Marshall Plan, the United States’ blueprint for aiding and rebuilding war-torn countries in Europe and a subtle strategy too in installing capitalism and repelling communism, represented an insidious effort to implement the Truman Doctrine.
The amended version is what the text means, though the text twisted it a bit to befuddle readers. You may see the //ism now between ‘a blue print for aiding and rebuilding’ and ‘a subtle strategy too in installing capitalism and repelling communism’
In B, ‘for aiding and rebuilding’, essentially prepositional phrases are not in rhyme with the Infinitives ‘to install and to repel’.
B looks more like a camouflaged pitfall to me, as I noted that it looks tempting.
But the OA is B I believe. So I admit that my reasoning is too far extended

Got you!!! I didn't consider flipping. Now that it's flipped, it makes more sense indeed. thanks