The correct answer is option 1: the presence of mycotoxin in them.

Molds are a type of fungi that can grow on various types of food, including cereal and grain products. When these foods become contaminated with molds, they can produce mycotoxins, which are toxic substances. Mycotoxins can be harmful to human health if ingested.

Option 2, the presence of phycotxin, is not correct. Phycotoxins are toxins produced by certain types of algae, not molds. Therefore, phycotoxins would not be present in molds contaminated cereal and grain products.

Option 3, the presence of maximum protein and starch, is not correct. While molds can degrade the nutritional content of food, their presence does not necessarily increase the levels of protein and starch. In fact, molds can break down proteins and other nutrients, potentially reducing their nutritional value.

Option 4, their foul smell, is not the primary reason why molds contaminated cereal and grain products are unfit for consumption. While molds can produce unpleasant odors, the presence of mycotoxins is the main concern because they pose a health risk.

In conclusion, the presence of mycotoxins in molds contaminated cereal and grain