Correct

救兵

/ jiù bīng / 
Strokes

Definition

reinforcement

Example

As a Noun

relief troops; reinforcements

1
Jiùbīng
救兵
zhèngzài
正在
túzhōng
途中
  
。

The reinforcements are on the way.

2
Nèi
内
wú
无
liángcǎo
粮草
  
,
wài
外
wú
无
jiùbīng
救兵

have no provisions within nor reinforcements without―be left utterly helpless

3
Bān
搬
  
/
diào
调
  
/
pài
派
jiùbīng
救兵

call in/bring up/dispatch reinforcements

As a Noun

rescue worker; rescuer