If a Forester Treats His Soil with a Broad-Spectrum Fungicide

If a forester treats his soil with a broad-spectrum fungicide, how would this affect the rate of CO₂ released from the system?

A) CO₂ released from the system will remain the same because fungi only decompose dead organisms and the forest is alive.
B) CO₂ released from the system will decrease because this would decrease the number of decomposers in the system.
C) CO₂ released from the system will increase because the fungi will be decomposed by something else.