Kublai Khan and The expansion of the Grand Canal finished with helps trade. Is that sentence of Kublai Khan Job Experience, Knowledge, Understands Me, Honest or Ethical, Tolerant? Please explain your answer, thank you :)

Which source would best a historian understand the effect of the great chicago fire on families? a. a biography of a chicago family displaced by the fire b. a letter from a grandmother in new york to her family in chicago c. a newspaper editorial about families who were displaced d. an oral history dictated by an adolescent who fled the fire