People's television-viewing habits could be monitored by having

Dear USADream,

I'm happy to help. This is a great question.

First of all, you may find this blog, on Evaluate the Argument CR questions, helpful:
https://magoosh.com/gmat/2013/gmat-criti ... onclusion/

Keep in mind, one the traps on this question format --- often, there are a few issues floating around in the argument, and the prompt question asks us to focus only on one. Therefore, anything related to the other issues, while relevant to the argument overall, is not relevant specifically to the issue on which the prompt question zeroes in. Here, one such issue would be the larger question --- would this design effectively and accurately measure how many people are watching TV? That would be relevant in the larger sense, but it's completely irrelevant to the prompt question, which very specifically is focused on health effects. Without even looking at the answers, I could predict that one or more incorrect answers would address the measurement issue.

Let's look at the answers:
A. Whether the proposed method of monitoring viewership can distinguish between people and pets
Relevant to the large issue of --- would this measure things accurately? --- but not relevant to health effects. This is incorrect.

B. Whether radar speed monitors also operate on the principle of analyzing reflected waves of electromagnetic radiation
An interesting analogy, but radar detectors hit cars, which presumably blocks most of the radiation from hitting the human body of the driver/passengers, whereas these TV zapper things will be shot right at the people sitting there. This is not particularly helpful, so it is incorrect.

C. Whether the proposed system has been tried out in various areas of the country or in a single area only
More data is always good, but suppose we had a literal answer to this --- "Yes, tried in various areas" or "No, only in a single area" --- if we just had that information, that answer, it wouldn't necessarily tell us anything. This is incorrect.

D. What uses are foreseen for the viewership data
This touches on juicy issues of civil liberties and government monitoring of private information, all of which could play into the larger discussion of whether this system would be legal or morally correct or consistent with the US Constitution, but none of these are relevant to the health effects. This is incorrect.

E. Whether the average dose that the proponent describes is a short-term dose or a lifetime cumulative dose
Ah, this one is relevant to the health effects. First of all, a single chest X-ray is a wallop of radiation ----- if folks get more than, say, two in a year, that's too much. If each session of watching TV with this zapper system is equivalent to a single chest X-ray dose, that would be bad enough, but if each session of watching TV were a lifetime's dose of X-rays, then it would be absolutely frying the poor TV viewers. This one is highly relevant to health effects, so this is the correct answer.

Does all this make sense?
Mike