Fill in the blank: The Mandate of Heaven justified rebellion against an ____________________________. If a rebellion was successful in overthrowing the emperor, then ______________________________________.

a
unjust or incompetent ruler; a new law was made
b
emperor; a new law was made
c
emperor; it was a sign that he had lost the Mandate of Heaven and the rebel leader had gained it.
d
unjust or incompetent ruler; it was a sign that he had lost the Mandate of Heaven and the rebel leader had gained it.