A client with coronary artery disease (CAD) is admitted to the medical unit for testing. The client describes having had frequent episodes of angina over the last few days prior to admission. The client is now experiencing shortness of breath, nausea, and chest pressure. After obtaining the client's vital signs, which action should the nurse take next?
A) Initiate dim lighting, lower alarm volumes, and control traffic in and out of the room area.
B) Count and record the number of premature ventricular contractions per minute.
C) Verify troponin level assessments are scheduled every 3 to 6 hours for a series of three.
D) Apply oxygen via nasal cannula and titrate to keep oxygen saturation above 93%.