单项选择题

Questions 29 and 30 are based on the following news. At the end of the news item, you will be given 10 seconds to answer the questions.
Now, listen to the news. Nigeria returned to the Commonwealth after______.

A.it had sentenced minority rights activists to death
B.the military had resumed control of the country
C.power had been handed over to an elected president
D.it had negotiated with Commonwealth leaders