Which one of the following proved effective for biological control of nematode diseases in plants?

Correct Option (b) Reason : Paecilomyces lilacinus is a fungus which principally infects eggs of root knot nematode (Meloidogyne sp.) and cyst nematodes (Gobodera and Heterodera sp.)

It has been considered to have greatest potential for application as a biocontrol agent in sub-tropical and tropical agricultural soils.