When Henri wants to share information with Chantal but not with others in the room, he stops speaking English and speaks French, which Chantal understands. Which scenario best describes Henri's attempts to keep his comments to Chantal private?

A. He decodes his message in a way he thinks only Chantal will understand.
B. He changes the cultural context of the message in a way he thinks only Chantal will understand.
C. He changes the temporal context of the message in a way he thinks only Chantal will understand.
D. He encodes his message in a way he thinks only Chantal will understand.

Answer: D