Questions 14 to 16 are based on a talk on pruritus, so called "severe itching"—why and how body parts itch. You now have 15 seconds to read Questions 14 to 16.

What is the positive side of pruritus

A．It arises from the irritation of skin cells or nerve cells.
B．It can be an unbearable nuisance.
C．It is a dominant symptom of many skin diseases.
D．It serves as a sensory and self-protective mechanism.