[单选题]2) Katherine Connor started her day with a cup of coffee while reading the newspaper. However, something about the day makes her feel low. When she reaches the office, she feels upset and distracted from work although she cannot pinpoint a reason for feeling this way. She continues to feel upset and distracted through the rest of the day. Which of the following is she most likely to be experiencing?   A a response B a reaction C a counteraction D an attitude E a mood