一个英语单选题----高手帮忙
Aspecialfeelingcametohim.Thesewerethefirstkindwordshehadeverheard.Hewatchedher______shewentfaraway,andhewhistled(吹口哨)tohisdogandwentdirectlytotherivernearby.
A:untilB:beforeC:whenD:while
最后请标准翻译这一小段,