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:  <1> Methylcellulose <2> Glycerin. <3> Loperamide. <4> Methylnaltrexone <5> Racecadotril.
4