Which of these is not an inorganic fungicide?

Answer: Option D

Oxathiin is not an inorganic fungicide from the given options.
It is a six-membered, unsaturated heterocycle containing four carbon atoms, one sulphur, one oxygen atom and two double bonds.
The current study shows that certain oxathiin carboxamides are selectively active against particular mutated SDCs of U. maydis and A. nidulans.