Sarah is a breast cancer patient. Her doctor arranged her for chemotherapy, for the period of 3 months. She feels nauseated and vomited every time after the chemotherapy. After first few sessions, she starting to demonstrate feelings of anxiety a few days before the chemotherapy session. She will have symptoms of feeling worried, feeling sad and reluctant to go. And on the day for the chemotherapy, she starts to feel nauseated by the thought of receiving chemotherapy, even if she has not received the injection. And on her way to the hospital, she
feels worse as she gets closer to receiving chemotherapy injections.

a) Explain the behavior shown by Sarah using the classical conditioning concept. 

b) In what way can psychologists help Sarah to reduce her anxiety and feeling of nausea?