Phytoplasma was 1st observed in

Answer: Option B

Phytoplasma was 1^st observed in Mulberry dwarf.
Phytoplasmas were discovered in 1967 by Japanese scientists who termed them mycoplasma-like organisms.
Phytoplasmas can be found as far back as 1603 in mulberry dwarf disease in Japan. Such diseases were originally thought to be caused by viruses, which, like phytoplasmas, require insect vectors, and cannot be cultured.