Fishy smell found in wheat field infected with karnal bunt is because of

Answer: Option B

The fishy smell found in wheat fields infected with karnal bunt is because of Trimethylamine.
Karnal bunt attacks durum wheat, rye, and triticale, a hybrid of wheat and rye. The smut fungus Tilletia indica, a basidiomycete, invades the kernels and obtains nutrients from the endosperm, leaving behind waste products with a disagreeable odor.
The disease produces dark color and a fishy smell on infected kernels. The odour is caused by the production of trimethylamine by the fungus.