Explanation

here the key word to look is the very first word Although .

This signals a contrast incoming; actually, soon we will have a shift in the second part of the sentence. So, if you do have a positive tone in the first part, then follow a negative word to fill the blank in the second part of the same.

A and B are positive word and E is out of scope. The station does not overshadow anything. looking at D could be the answer but at a close look it is still positive in its meaning. C means weaken.

C is best
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What will happen if city inhabitants are moved to suburbs?

The city will lack efficiency and will weaken. Thus enfeeble fits there appropriately.