Which of the following is a common sign of shock in a patient?

A rapid heart rate and pale skin are indeed common signs of shock in a patient. Shock is a critical condition that occurs when the body is not getting enough blood flow, resulting in inadequate oxygen delivery to tissues and organs. The rapid heart rate is the body's compensatory mechanism to try to maintain adequate circulation and blood pressure in response to the low blood volume or inadequate perfusion. Pale skin is often observed due to vasoconstriction, where blood vessels narrow to redirect blood flow to vital organs, leading to diminished blood flow to the skin.

Other options, while they may represent symptoms associated with different medical conditions, do not accurately reflect the typical presentation of shock. Increased energy and alertness would not be consistent with shock, as affected individuals usually exhibit signs of weakness and confusion. A strong pulse and flushing of the skin may indicate other medical issues, such as fever or anaphylaxis, but they do not align with the classic signs of shock. Fever and chills typically suggest an infectious process rather than shock. Thus, rapid heart rate and pale skin are key indicators, making this choice the correct one.