Final answer:
To decrease CO exposure from CO₂ absorbent, the correct action is to increase fresh gas flow, which reduces the amount of CO2 being recirculated and absorbed.
Step-by-step explanation:
To decrease CO exposure from CO₂ absorbent, the correct approach would be a) Increase fresh gas flow. By increasing the fresh gas flow through an anesthesia circuit, less exhaled CO₂ is recirculated and absorbed by the CO₂ absorbent, which means that less CO is produced as a by-product of the reaction with the absorbent materials. Options b) Decrease fresh gas flow and c) Use a closed system would actually increase CO₂ absorption, thus potentially increasing CO exposure if the absorbent is degraded or exhausted.