💡 Detailed Explanation
'屈服する' (kuppuku suru) means to yield or submit to pressure or difficulty. It is most suitable here for the context of continuing to strive without yielding to the difficult situation of years of misfortune. '頓挫する' (tonza suru) means for a plan to get bogged down. '畏縮する' (ishuku suru) means to shrink back in fear. '挫折する' (zasetsu suru) means to be frustrated, to fail, or to give up on a goal due to difficulty, which is a strong distractor but '屈服' more directly expresses not being defeated by external circumstances.