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

$\begin {array} {1 1} (1)\;Paecilomyces\:lilacinus & \quad (2)\;Pisolithus\: tinctorius \\ (3)\;Pseudomonas\: cepacia & \quad (4)\;Gliocladium\: virens \end {array}$