Which is the most important source of food and fodder?

1. algae
2. fungi
3. lichen
4. cereal

Correct Answer: (d) cereal

Explanation:

 Cereal is the most important source of food and fodder.

After harvesting cereals from the crops, such as rice, wheat, sorghum, etc., the remaining stalk or hay is used as fodder for the cattles.