I'm not completely certain but I believe that the answer is dehydration. When this occurs, monosaccarides are joined and water, or H2O, is a product of this.
B replaced because it takes place when water dissolves the original hard parts and replaces them with mineral matter.
Can cause acid rain because the chemicals mix with the water vapor
HETEROTROPHS
Explanation:
Autotrophs are any organisms that are capable of producing their own food. For most, this is achieved by using light energy, water and carbon dioxide. Heterotrophs cannot produce they have to absorb.
They help an environment because they create an ecosystem allowing animals to thrive and live a lifecycle with the resources they need.
