Bamboo flowering causes:

Correct option is A

Bamboo flowering causes an increase in the population of rats.
 Bamboo flowering triggers a boom in the rat population, as bamboo seeds provide a plentiful food source for rats. This is commonly known as a rat or rodent plague.
 Bamboo flowering primarily affects the bamboo population and the ecosystem around it, but it does not render the land infertile.
An increase in rats could lead to an increase in certain pests that prey on them, it is not a direct consequence of bamboo flowering