Answer: Context
Step-by-step explanation:
Change in context is defined as modification or change that occur in the circumstances of the environment.If setting of this environment gets altered then change takes place.
According to the question,change in context made Ralph change his tone and words .As Ralph was dictating his story in front of her friend he has particular circumstance but as his mother entered the room, circumstances got changed because it is not appropriate to use profanity and loud voice in front of her.