What is a sign of shock?

Restlessness is indeed a sign of shock. When a person is in shock, their body is not receiving enough oxygen and nutrients due to insufficient blood flow, which can lead to symptoms such as anxiety, agitation, or restlessness. This state is predominantly a response to the body trying to cope with the decreased oxygen levels and the stress of the condition.

To understand the context of why other choices do not indicate shock: an increased appetite would likely not be associated with shock, as the body typically prioritizes survival functions over digestion when in distress. High blood pressure is usually not a sign of shock; in fact, shock often presents with low blood pressure due to decreased circulating blood volume. Firm abdominal muscles may suggest tension or guarding in response to pain rather than a symptom of shock, as physical signs could vary based on the underlying cause of shock but are not typical indicators of it.