Correct

软肋

/ ruǎnlèi /
Strokes

Definition

rib cartilage/(fig.) weak spot/soft underbelly

Example

As a Noun

weak point; Achilles heel

1
men
他们
qiúduì
球队
de
jìngōng
进攻
jiàng
  
,
dàn
fángshǒu
防守
ruò
jiāng
chéngwéi
成为
men
他们
de
ruǎnlèi
软肋
  

As a team they're strong on attack but they have a weak defence that might prove to be their Achilles'heel.

2
Ài
chūfēngtou
出风头
chéng
le
de
ruǎnlèi
软肋
  

The desire for publicity became her Achilles heel.