The Stimulus in This Scenario Is

The stimulus in this scenario is

A) the increase in carbon dioxide concentration in Jane's blood while she is holding her breath.
B) the impulses sent to the medulla oblongata.
C) the more frequent inhalations and exhalations.
D) the decrease in carbon dioxide concentration as she breathes more forcefully.
E) Jane diving into the swimming pool. The stimulus is whatever has deviated from within the normal range.