All known PPN nematodes possess

Answer: Option C

All known PPN nematodes possess Stylet.
A stylet is a hard, sharp, anatomical structure found in some invertebrates.
The word stylet or stomatostyle is used for the primitive piercing mouthparts of some nematodes. In these groups, the stylet is a hardened protrusible opening to the stomach.
These stylets are adapted for the piercing of cell walls and usually function by providing the operative organism with access to the nutrients contained within the prey cell.