Question

Which line from the text demonstrates an inverted syntax?

In the deserted, moon-blanch'd street,
How lonely rings the echo of my feet!
Those windows, which I gaze at, frown,
Silent and white, unopening down,

Answer 1

The answer is B. How lonely rings the echo of my feet! (hopes this helps) 

Answer 2

Here's an example of inverted syntax:
Normal syntax: Jane ate a cake.
Inverted syntax: A cake Jane ate.

I think that the second line probably has inverted syntax, since you can re-write it as shown below:
Sentence given (inverted): How lonely rings the echo of my feet!
Sentence re-ordered (normal): The echo of my feet rings lonely.

EDIT:
I think I made a mistake above ^
I believe its actually line three, which can be re-ordered to read: I gaze at those windows which frown