My father is annoyed by people who think that the world owes anything. There is the relative pronoun WHO which its antecedent is people
The Mandate of Heaven is an ancient Chinese belief and philosophical idea that Heaven (天; Tian) granted emperors the right to rule based on their ability to govern well and fairly. According to this belief, heaven bestows its mandate to a just ruler, the Son of Heaven, and withdraws it from a despotic ruler, leading to the overthrow of that ruler. The Mandate of Heaven would then transfer to those who would rule best. The fact that a ruler was overthrown was taken by itself as an indication that the ruler had lost the Mandate of Heaven.
So, the right answer is A The Zhou Dynasty’s justification for its leadership.