To check for arterial insufficiency when a
题型：单项选择题
问题：
To check for arterial insufficiency when a client is in a supine position, the nurse should elevate the extremity at a 45-degree angle and then have the client sit up. The nurse suspects arterial insufficiency if the assessment reveals which of the following（）
A. Elevational rubor.
B. No rubor for 10 seconds after the maneuver.
C. Dependent pallor.
D. A 30-second filling time for the veins.