Correct

作壁上观

/ zuō bì shàng guàn / 
Strokes

Example

Definition

watch the fighting from the ramparts—sit by and watch; be an onlooker/by-stander

1
Tāmen
他们
chǎo
吵
de
得
bùkěkāijiāo
不可开交
  
,
nǐ
你
yào
要
qù
去
zhìzhǐ
制止
  
,
bù
不
néng
能
zuōbìshàngguàn
作壁上观
  
。

They are quarrelling fiercely. You should go and stop them rather than sit and watch.