Usage of "Whose" is GMAT is quiet flexible. It not only modifies people but also modifies places. For more on this refer to OG-12 SC 102

b and e have parallelism error, moreover

fact that... - is a redundant construction

The fact that GMAT is tough cannot be denied - redundant
That the GMAT is tough cannot be denied. - best

left with A,C and D

C is wrong as stated by you - we are not clear what does "whose" refer to.

D is wrong for the usage of "thus"
- "thus" is used to draw conclusion, you can refer some CR problem regarding the usage of "thus". So here "thus" has a wrong usage. "And thus reduce..." - is not the conslusion here

Hence, A is the correct one. For more usage of with refer to this threads -

https://www.beatthegmat.com/comma-with-v ... tml#423388
https://www.beatthegmat.com/correct-usag ... 92756.html

hope this helps !!

In (C) whose modifies the marine world (closest);

I think the key to solve this SC is to understand the meaning of the sentence, the failure is due to depiction with emotional over tones;
If the meaning is not clear, as Avi suggested just eliminate choices that have redundancies and awkword
sentence structures.

Good one!!

(A) depiction of scenes of life and death in the marine world with emotional overtones that - IMO CORRECT
(B) fact that it depicts marine world scenes of life and death as having emotional overtones that - INCORRECT - ambiguous use of 'it'
(C) depiction of scenes of life and death in the marine world, whose emotional overtones - INCORRECT - emotional overtones refers to the marine world
(D) depiction of marine world scenes of life and death, which have emotional overtones and thus - INCORRECT - marine world scenes -incorrect idiom and who resuces the credibility is not clear. Incorrect usage of Thus.
(E) fact that it depicts scenes of life and death in the marine world, whose emotional overtones - INCORRECT - not clear whom is 'it' referring to.

Hence IMO (A)

Understanding the meaning of the original sentence is always the key.

It should be evident that the original sentence is talking about the fact that the depiction (of scenes of life and death) has emotional overtones; C changes the meaning completely by stating that marine world has emotional overtones.