Von Schmeling and Kulka first time demonstrated the systemic activity of fungicides in

Answer: Option B

Von Schmeling and Kulka first time demonstrated the systemic activity of fungicides in 1966.
A SYSTEMIC fungicide may be defined as a fungicidal compound that is readily translocated as such in the plant, rendering the tissues penetrated toxic to fungi.
In their treatment they treated pinto bean and barley seed with 1,4-oxathiin derivatives gave disease control by systemic fungicidal action of such pathogenic fungi as Uromyces phaseoli and Ustilago nuda.