Answer:
C. a preoccupation with the idea of being sick
Step-by-step explanation:
Hypochondriasis and pain disorder are two conditions that deviates from the normal human health. Hypochondriasis, also known as health anxiety, is a condition whereby an individual is fearfully worried about having a serious illness. On the other hand, pain disorder is a condition in which pain results in certain areas of an individual's body due to psychological disposition of such individual i.e. his/her mindset.
Based on the description of both conditions above, it can be observed that both hypochondriasis and pain disorder are as a result of a preoccupied mindset of being sick. One is worried PSYCHOLOGICALLY about being terribly ill (Hypochondriasis) while the other PSYCHOLOGICALLY induces pain on him/herself.