Which of the Following Is True of the Method of Ventilator

Which of the following is true of the method of ventilator weaning called spontaneous breathing trials (SBT) ?

A) Mechanical ventilation can be discontinued if patient cannot tolerate as little as 30 minutes off
B) SBT is the same as SIMV mode of ventilation
C) Measurements of cardiac output and SvO₂ are essential
D) Sedation can be given if a patient begins to have difficulty with breathing