While manually ventilating an intubated patient in preparation for suctioning, the nurse tries to deliver the same PIP that the ventilator was delivering but can only deliver inspiratory pressure that is lower than desired. To resolve this issue, what action should the nurse perform?
A. Open the flow-control valve slightly.
B. Close the flow-control valve slightly.
C. Increase the frequency of ventilations.
D. Change the reservoir bag to a larger size one.