Brenda is from the netherlands and has made every attempt to "fit in" with her new american friends. while they may not be consciously aware of it, those friends have also been trying to adapt to brenda's communication behaviors. this is illustrated in

This is illustrated in communication accommodation theory.
The theory was first proposed by Howard Giles in the 20th century. According to the theory, we try to accommodate into our partner's communication as much as they are trying to accommodate into ours. So in this case, both Brenda and her American friends have been trying to adapt to each other's behavior when it comes to communication. 

The answer is eastern europe