Physical noise can be one obstacle to effective communication. Physical noise refers to the existence of external stimulus that does not allow us to receive a message sent by a communicator, or to receive it accurately. This includes things such as background noise. In this case, the existence of loud music at a party would be considered physical noise.
Answer choice C makes a claim that the three trees are similar, but have differences. This makes for an excellent set up to compare (similar) and contrast (different)!
