Jasmine was holidaying with her family in a wildlife park ________ she was bitten on the leg by a lion．

A.when

B.while

C.since

D.once

答案及解析： A

解析：

while引导的句子中的谓语动词为延续性动词或状态性动词；

when引导的句子中的谓语动词可为延续性或非延续性动词．bite为非延续性动词，when在此处为并列连词，意为“这时”．