...and, just as importantly, you didn't mention any alternative options.
i.e., if the question had presented an alternative version in other answer choices, you wouldn't have written your post the way you did. rather, you would have written something like 'i have to choose between may and might.'
this is the real reason why i could tell this wasn't in the underlined part. (sometimes the underlined part DOES contain these kinds of 'decisions'... but only as distractions from much easier, much more fundamental things.)