The correct option is D Lady birds
Biocontrol is the use of living organisms, such as insects or pathogens, to control pest populations. It is an alternative method to overcome the plant diseases instead of using chemicals.
Beetles, ladybirds and dragonflies are used as biocontrol agents to get rid of aphids and mosquitoes, respectively. Therefore farmer's can use ladybirds to control aphids since his crops are being destroyed by aphids.