The first clinical trial of an Ebola vaccine in the outbreak described in the newspaper began in which country?

Correct: A. The WHO chief announced that participants in Bunia, Democratic Republic of Congo, received the first doses in the new Tumaini vaccine trial.

B appears elsewhere in the paper in connection with a church attack, not Ebola research.

C is associated with regional conflict and medicine-delivery reporting, not this trial.

D appears in a separate intelligence-related story and is not the trial location.