COULD YOU PHONE ME ___________ YOU ARRIVE AT GRANDMOTHER’S SO I DO...

23. - DE O THI DAI HOC VA DAP AN THAM KHAO
DE O THI DAI HOC VA DAP AN THAM KHAO

23. Could you phone me ___________ you arrive at grandmother’s so I don’t worry?

A. where B. the time C. the moment D. the hour