Ustilago caused plant diseases are called smuts because

Options

A. They parasitise cereals
B. Mycelium is black
C. They develop sooty masses of spores
D. Affected parts become complectely black.

Answer

D

Explanation

Both C and D are correct, since C is the trait of the fungus while D represents the effect on host. When the choice is between the two , the language of the question becomes important-plant disease is called smut, that is the effect on the host .