Concept:Stress pattern refers to the syllable that receives the most emphasis in a word.Explanation:The word “calender” is stressed on the first syllable: CAL-en-der.The word “aloud” is stressed on the second syllable: a-LOUD.The word “mechanic” is stressed on the second syllable: me-CHAN-ic.The word “convivial” is stressed on the second syllable: con-VIV-ial.Only “calender” has the stress on the first syllable, while the other options have stress on the second syllable.Therefore, “calender” has a different stress pattern.Answer:A. calender