The Elderly Client Has Constipation

The elderly client has constipation. He asks the nurse the reason for this. What is the best response by the nurse?

A) "You could have a serious illness, and should check with your doctor."
B) "You probably drink too much alcohol, and end up constipated."
C) "Your large intestine is old and does not work as well as it used to."
D) "You don't eat enough fibre, so the stool stays in your intestine too long."