-I hope you'll enjoy your trip,dear!-Thank you,mum.I'll give you a call____I get there.A.until B.as soon as C.since D.till为什么选D呢?B为什么不对?

-I hope you'll enjoy your trip,dear!-Thank you,mum.I'll give you a call____I get there.
A.until B.as soon as C.since D.till
为什么选D呢?B为什么不对?

不对吧,答案应该是B 呀
我一到达那里就给你电话.

B.as soon as