GMAT Sentence Correction (SC) | Re: Under high pressure and intense heat, graphite, the most

Under high pressure and intense heat, graphite, the most stable form of pure carbon, changes into the substance commonly referred to as diamond andremaining this way whether or not the heat and pressure are removed.

(A) remaining this way whether or not - Parallelism issue - changes and remaining . Also we need simple present tense here as the sentence states a fact about graphite.
(B) remaining like that even as - Parallelism issue - changes and remaining . Even as is incorrect
(C) remaining
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