Back when I was in school, we had an honors class focused on test taking. One of the exercises we did was taking multiple choice tests where we were unlikely to know or understand the content being tested.
The idea was to read through the test and quickly scan for information that could be used to answer other questions on the test.
After doing that and filling in the answers that were provided by the material itself, you looked for predictable patterns in the answers; this differed depending on the test. For an answer key created by hand where the test writer doesn’t know about “pick c” C is the best answer. But these days, test writing software usually “randomizes” the answer order, attempting to make each answer a truly random letter.
But “random” is rarely truly random, and the human eye can often spot distributions and patterns once enough answers have been filled in.
And this brings us to the key bit: usually with multiple choice there will be one answer that’s obviously wrong, one correct answer, one answer that illustrates you understand the technique but not the general concept, and one that reflects a common error.
If you can identify which answer is likely to be each of those, they’ll also have a distribution and a pattern, and these can help you eliminate incorrect answers and highlight the correct solution.
Using these analytic techniques, it’s usually possible to score at least 80%, although the success rate generally improves with the length of the test and the amount of time provided to do the analysis.
We had it drilled into us that, after we’d filled out the answers based on our knowledge and skill, to ALWAYS leave time to go back and run these techniques against the test to ensure that we hadn’t made mistakes AND to gain a deeper understanding of the particular test writer to apply against their future tests.