An Older Person Is Seen Talking and Laughing in the Clinic's

An older person is seen talking and laughing in the clinic's waiting room, yet complains of excruciating pain. The nurse realises this person is most likely demonstrating which of the following?

A) Inconsistent behavioural response to pain.
B) The desire for narcotics.
C) Denial of his level of pain.
D) Pain tolerance.