【正确答案】
C
【答案解析】[解析]
Fighting flared yesterday in northern and southern Bosnia, pitting Serbs against Muslims and Muslims against Croats. Meanwhile, Bosnian Serbs voted on a peace plan they seem certain to reject. The defiance of Bosnian Serbs and the three-way fighting underlined the complexity of bringing peace to this rugged state. A brutal 13-month war had destroyed its elaborate ethnic quiet, stitched together by centuries of coexistence.
The United States President had dismissed this weekend's Bosnian Serb referendum as a maneuver to buy time. He is expected to press reluctant Europeans for military action against Bosnia's Serbs if they do reject the apparently doomed Vance Owen plan.
[解析] 题目问的是三个种族发生混战时，塞尔维亚人就一项和平计划进行投票发生的时间。新闻中首先提到昨天又展开了激战，接着提到“Meanwhile, Bosnian Serbs...certain to reject”，由此可见，两件事是同时发生的，故答案为[C]。