On SAT reading I narrow it to two answers and then pick the wrong one. Why?

Because at that point you are choosing on which answer sounds more reasonable, and both will. The test is built so the final two both look plausible. The way out is to stop comparing the options to each other and start comparing each one to the text.

Find the line, then decide

The question is never asking what is true in general. It is asking what this passage says or implies.

So before comparing the two survivors, go back and locate the specific sentence or sentences that would have to be true for each one to be correct. One of them will have a line behind it. The other will be something the passage gestures at but does not actually state.

If you cannot point at the text, the answer is wrong, however sensible it reads.

The four ways a wrong answer is built

Plausible wrong options are not random. They are constructed, and they recur:

Too extreme. The passage says a policy "had mixed results"; the option says it "failed". Watch for always, never, all, none, proves, impossible. Passages are usually hedged; answers that are not hedged are usually wrong.

Right idea, wrong part of the passage. True of paragraph two, but the question asked about paragraph five. Easy to fall for because it feels familiar.

True but not the answer. The statement is accurate and the passage supports it, but it does not answer the question asked. Reread the question stem before committing.

Half right. The first clause is correct, the second adds something the passage never says. Read the whole option, not the opening.

Running the two survivors through those four tests resolves most of them.

Answer in your head first

Before looking at the options, decide roughly what the answer should be and put it in your own words. Then look.

This matters more than it sounds. Reading the options first lets them reframe the question, and a well-written wrong answer is specifically designed to be attractive when you have not already formed a view. With your own answer in mind, you are matching rather than being persuaded.

When two answers really do both work

Occasionally you will test both against the text and both survive. In that case look for scope. One answer is usually about a detail and the other about the passage as a whole, and the question stem tells you which it wants.

"The author's primary purpose" wants the whole. "In line 34, the author suggests" wants the detail. Students who mismatch scope get questions wrong while understanding the passage perfectly well, which is the frustrating version of this mistake and also the easiest one to stop making.