Which One of the Following Teachers Is Sending an "I

Which one of the following teachers is sending an "I" message to a student?

A) "With all the noise that you're making while I'm teaching, I am unable to be heard by students at the back of the room, and I am frustrated."
B) "I hear you saying that you do not understand what Mary is saying."
C) "I like David's suggestion. It shows a lot of imagination, so let's try to use it."
D) "I think that Sam should be given the benefit of the doubt about this issue."