Answer:
The answer would be the last one, he is examining the physical characteristics. Why this is correct is because physical characteristics are visible to the naked eye and therefore everything he stated was just that, including color and shape/design
Explanation:
The correct answer is a nutrient runoff.
Nutrient runoff is a major reason for eutrophication of surface waters, in which extra amount of nutrients, generally phosphorus or nitrogen, instigate growth of algae. Sources of nutrient pollution involve surface runoff from pastures and farm fields, emissions from combustion, and discharges from septic tanks.
They go straight through the ocean?
Sickel cell anemia is an inherited disease that is due to a base substitution mutation in a gene.