Main point

Why is the answer choice "B" and not "E"? Considering choice "E" addressed the importance of employing the double-blind technique to evade misinterpretations that derived from biased expectations and opinions.

Just offering some help to the person above; the answer is B and not E because B refers back to main point of the argument. That the double blind technique should be employed as often as possible, while E reiterates evidence used to support that conclusion.

Identifying the conclusion will almost always get one to the answer in main point questions! And the above poster is correct: "E" supports the main conclusion by offering evidence in support of adopting it, while "B" addresses the main point itself.

I originally chose E as well, but now see that B is the only one that restates, "Double-blind techniques should be used whenever possible in scientific experiments.", whereas E supports that statement.

The difference is that B is prescriptive, like the conclusion, it tells us what we should do. E is merely describing double blinds.