Cho mnh hỏi sự khc nhau giữa among v amid với

When he was finishing up, he found a loose wire which he connected the other day, so he had to reconnect it. However, it appears that when reconnecting it, he made some mistakes. ........... the machines affected were the new NS3, one of the primary name servers, and Happer, which controls the new operating system

A. Among
B. Amid
C. So
D. Until

Giải thch gip mnh nh