GMAT Critical Reasoning (CR) | Although parapsychology is often considered a pseudoscience,

Hi Experts,
Can you please elaborate POE (C vs D) based on necessary vs sufficient condition.
I read through trailing answers and am convinced with usage of 'because' in case
of 'for it uses' in original sentence but does not conditional statement needs to be if ..
then ..construction and not causal reasoning format?

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