This is a barrier caused by:
B) semantics and connotations
Step-by-step explanation:
Here, one can see clearly that the reason the person is facing a cultural barrier is not because she is not entirely familiar with their culture but due to subtle difference in the way the people talk.
This greeting is a subtle difference, however it reveals quite a lot about a person and here it betrays that she is not a native.
This barrier is thus caused by the semantics of her common language that can differ from Nation to nation.