I was taking a quiet walk last night when, ___________, there was a loud explosion. A. all in all B. all at once C. suddenly at once D. once at all

I was taking a quiet walk last night when, ___________, there was a loud explosion.

A. all in all: nói chung, nhìn chung

B. all at once: bất thình lình, một lúc

C. suddenly at once: vô nghĩa

D. once at all: vô nghĩa

@MinhBestEngg