Which of the Following Led to the End of White

Which of the following led to the end of white minority rule in Rhodesia in 1979?

A) International diplomatic pressure led to a peaceful transfer of power to Robert Mugabe.
B) White minority rule ended when Britain granted independence to all its African colonies.
C) Independent African states supported a successful guerrilla movement under Robert Mugabe.
D) African nationalist movements had exhausted Portuguese resources, leading to their withdrawal.