Correct

密件

/ mìjiàn / 
Strokes

Definition

secret documents/abbr. for 机密文件

Example

As a Noun

confidential paper/letter; classified matter/material

1
Fà
发
  
/
xiě
写
mìjiàn
密件

post/write a confidential paper

2
Yī
一
fèn
份
  
/
gè
个
mìjiàn
密件

a confidential paper