In this task, you are given a question and answer options for that question. Using this information, you have to classify each text into different topics: medicine, nursery, psychology, chemistry, pharmacology, biology.

Question: Woman, 63 years old, in treatment for bone cancer. He has intense pains so he uses morphine daily. Faced with complaints of constipation, it is proposed as a laxative of choice:
Options: <0> Methylcellulose <1> Glycerin. <2> Loperamide. <3> Methylnaltrexone <4> Racecadotril.
pharmacology