Correct

黑账

/ hēi zhàng / 
Strokes

Example

As a Noun

private record; secret account

1
Jì
记
hēi
黑
zhàng
账

keep a private/secret record

2
Zhā
查
gāi
该
gōngsī
公司
de
的
hēi
黑
zhàng
账

investigate into the secret account of the company