Bacillus thuringiensis is used for the control of which of the following?

Which of the following has proven useful for controlling nematode diseases in vegetables,fruits,and cereal crops?

In the confusion technique,pheromone-coated paper strips are thrown over an area in order to:

Integrated Pest Management $(IPM)$ is based on which of the following?

Which virus is used as a biocontrol agent?

Assertion $A$: The use of biocontrol agents prepared by microorganisms has become necessary as an alternative to chemical pesticides.
Reason $R$: The use of biological control agents helps maintain the balance of the ecosystem.
Which option is correct for Assertion $A$ and Reason $R$?