Answer:
b. can consist of manure, crop residues, or bone meal is the correct answer.
Explanation:
Organic fertilizers are derived from the plant-based material and animal excreta, vegetable matter, animal matter, crop residues, and human excreta.
Examples of organic fertilizers are:
Organic fertilizers provide essential nutrients in the soil, improves the structures of soil, decrease the soil erosion caused by rain by increasing and improving the soil's capacity to hold the nutrients and water.