Which type of toxin known to the primary determinant of pathogenicity?

Answer: Option C

Pathotoxin type of toxin is known to be the primary determinant of pathogenicity.
A chemical of biological origin, other than an enzyme, that plays an important causal role in a plant disease is termed a Pathotoxin.
Potent molecules produced by a large variety of bacterial pathogens that target host cells and play key roles in the host-pathogen dialog. They are major virulence factors often sufficient to determine the outcome of the infection.