On His Way to Class,Isaac Overheard His Professor in the Hallway

On his way to class,Isaac overheard his professor in the hallway discussing those "radical Bible thumpers" with a fellow professor.Isaac felt a personal sting and just couldn't get the sound of that phrase out of his mind.Later,while in the professor's class,he found that he was taking poor notes and really didn't understand the lecture for that day.Which of the following best describes the cause of Isaac's failure to listen in class?

A) Self-focus
B) Emotional noise
C) Information overload
D) Environmental noise