Essential Features of Positive Pressure Ventilators That Are Used in Alternative

Essential features of positive pressure ventilators that are used in alternative care settings on patients with intact ventilatory drive and respiratory muscles include which of the following?
1) Mandatory minimum rate
2) Flow or inspiratory time control
3) Breath-triggering mechanism
4) Spontaneous breathe mode

A) 1 and 3 only
B) 1, 2, and 3 only
C) 3 and 4 only
D) 2, 3, and 4 only