Stomata Closure in Darkened Environment, at Time Zero, with Air

Multiple Choice

Stomata closure in darkened environment, at time zero, with air (0.03% CO₂) or CO₂-free airflow through leaf. (Note: A decrease in conductance indicates inactivation of the proton pump.)

A) Supports both Hypothesis I and II.
B) Supports only Hypothesis I.
C) Supports only Hypothesis II.
D) Supports neither hypothesis.