The ideal cities of Ebenezer Howard, Frank Lloyd Wright, and Le Corbusier, different from one another as they were, were all based on a belief that physical order in itself could bring about the good life.
A.
different from one another as they were
Correct usage of "different from one another" idiom.
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B.
different one from the other as they were
"different one from the other" doesn't sound idiomatic.
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C.
different from each other as
every one was
"different from each other" doesn't sound idiomatic.
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D.
differing as each was, one from the other
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E. although each differed
fromMeaning error. Doesn't specify what the cities are different from.
INCORRECT________________________________________________________________________________________________________________
Hence option A