Which of the following actions should you take to reduce the cause of shock?

Controlling bleeding is a critical action to take in the event of shock because excessive blood loss is a primary factor in the development of shock. When the body loses a significant amount of blood, the heart struggles to pump enough blood to maintain adequate circulation to vital organs. This can lead to life-threatening situations. By applying direct pressure to the wound to stop bleeding, you can help stabilize the person's condition, preserve blood volume, and improve chances of recovery.

While other actions like calling emergency services, elevating the legs, or providing a moist cloth can support a person experiencing shock, they do not directly address one of its most immediate and serious causes. Elevating the feet may be appropriate in some cases but should not be prioritized over controlling active bleeding. Thus, controlling bleeding stands out as the most effective and essential action to mitigate the risk of shock.