Sentence Correction

Though viewed from a distance, Saturn's main rings may appear to be smooth and continuous, they are in fact composed of thousands of separate icy ringlets when viewed up close.

(A) Though viewed from a distance, Saturn's main rings may appear to be smooth and continuous, they are in fact composed of thousands of separate icy ringlets when viewed up close.
(B) Though Saturn's main rings may appear smooth and continuous when viewed from a distance, they are in fact composed of thousands of separate icy ringlets when viewed up close.
(C) Saturn's main rings, when viewed from a distance, may appear to be smooth and continuous, though when viewed up close they are in fact composed of thousands of separate icy ringlets.
(D) When viewed from a distance, Saturn's main rings may appear smooth and continuous, but closer viewing reveals them to be composed
of thousands of separate icy ringlets.
(E) Though composed of thousands of separate icy ringlets if viewed up close, the main rings of Saturn may appear smooth and continuous

[spoiler]IMO:D[/spoiler]

IMO: B

IMO B.

+1 for B. What is the OA?

The problem with B is that it suggests that the rings are composed of separate ringlets when viewed up close (as opposed to all the time).

Will go for D.
@gmatblood, what is the OA?

On a further look, I will go with D.

Please provide OA.

@Jim: Your take?

Thanks.

I picked D too

the meaning is -- Saturn rings appear smooth when viewed from a distance but they (rings) are actually composed of thousands of separate icy ringlets, when viewed up close. --This is what we can clearly understand from option D

@ Jim : I do not find any problems with the construction of B as far as the meaning is concerned. It seems the suggest the same thing what D does. This is,however, my opinion. Also, the passive construction of D could possibly raise eyebrows.

Please provide OA.

Thanks.