hairs on the back stand up when scared decreased heart rate when sleeping movement of waste into the bladder temperature increases during an infection
I gave my students this multiple choice question: Which of these is a response of cats to external stimuli?

Only one answer is correct among these 4 choices:
- hairs on the back stand up when scared
- decreased heart rate when sleeping
- movement of waste into the bladder
- temperature increases during an infection

Could you tell me which one is correct?

hairs on the back stand up when scared