Concept:Stress pattern refers to the syllable in a word that is pronounced with greater emphasis.Explanation:Option A: undo → stress is on the second syllable: un-DO.Option B: ado → stress is on the second syllable: a-DO.Option C: unless → stress is on the second syllable: un-LESS.Option D: legal → stress is on the first syllable: LE-gal.Thus, options A, B, and C have the same stress pattern, while option D is different.Answer:D. legal