Who is regarded as father of phytopathology?

Answer: Option D

Anton de Bary is regarded as the father of phytopathology.
Heinrich Anton de Bary was a German surgeon, botanist, microbiologist, and mycologist. He is considered a founding father of plant pathology (phytopathology) as well as the founder of modern mycology.
Plant pathology is the science that studies the causes of plant diseases, the mechanisms by which diseases develop in individual plants and plant populations, and the ways and means by which plant diseases can be managed or controlled.