Which of the following is a sign of shock?

A rapid heartbeat is a clear sign of shock, which occurs when the body is not receiving enough blood flow to meet its needs. In response to shock, the heart tries to compensate by increasing its rate to maintain adequate circulation and oxygen delivery to vital organs. This physiological response can be a result of various types of shock, such as hypovolemic, cardiogenic, or septic shock.

In a state of shock, other symptoms may include low blood pressure, confusion, and cool or clammy skin, but a rapid heartbeat is particularly indicative as it demonstrates the body's struggle to maintain blood flow under distress. Understanding the body's response to shock can help in identifying and managing this critical condition effectively.