You measure the patient's blood pressure and find him to be hypotensive. His blood pressure is 85/55. The nursing student adds that his normal pressure is approximately 140/90. Pulse oximetry reveals an oxygen saturation of 91%. What is the next action?
a) Administer intravenous fluids
b) Administer oxygen therapy
c) Initiate cardiac monitoring
d) Perform a 12-lead ECG