The conclusion is "Thus, as researchers claim, psychic phenomena will soon be explainable." The first sentence is nearly identical to this -- it tells us that yes, this is what they believe. The last sentence concludes "they're right."

The evidence is that psychic phenomena will be explainable after two conditions are met: 1) knowledge of how mental images are "sent" and "received" over distance and 2) knowledge of how senders and receivers interact at a biological level. The passage then says that condition 1 has been met.

But what about condition 2? Was this condition met? Simply assuming that it was is a flaw. Choice C points this out.

Your approach of this question should be the same as for nearly every type of CR question. Identify the conclusion and the evidence, and then consider what assumptions are made. When looking for an existing flaw, look for unwarranted assumptions. There are other types of flaws, but unwarranted assumptions is a biggie.

I'm available for further help with this question.