I believe the answer may be D!
Reasoning:
If a butterflies, or any bug with a predator, dominant predator was affected by the fungus and became quite scarce, the butterflies would be able to thrive more than before.
On a normal clover population, the butterflies would still thrive. However, with the constant threat of a predator looming in the air with them, many would die to the dragonflies. Therefor, the less dragon flies, the more butterflies.
