I believe the correct response is A. The population of secondary consumers would decrease, as now these organisms can't obtain energy through the food they consume which is the primary consumers as there is none and thus the population in higher tropic level dependent on them would decrease. This is the secondary consumer.
Answer;
-Analytical chemistry - composition.
Environmental - impact of chemicals
Explanation;
-Analytical chemistry involves the qualitative and quantitative determination of the chemical components of substances. In qualitative analysis all the atoms and molecules present are identified, with particular attention to trace elements. In quantitative analysis the exact weight of each constituent is obtained as well.
Environmental chemistry is the study of the chemical and biochemical phenomena that occur in the environment.It relies heavily on analytical chemistry and includes atmospheric, aquatic, and soil chemistry.
Answer - A. Deep because there is less O2 exchange
Reasoning - Bacteria has been known to only use half a percentage which is .5 percent of O2.