Exam question error?

[Olga]

Hi,

In the exam question 7654 it s mentioned that none of the presented signs refer to a deep canal next to the road?
Isn't the sign B the one that is regarding the deep canal?

It says the correct answer is C- none of the displayed ones.

I might be mistaken....

Thank you,
Olga

[GRO]

The meaning is:
Exit on a quay or a riverbank