To solve this problem, we need to match the items in Column I with the appropriate descriptions in Column II. Let's analyze each item:$\newline \bullet$a. Eutrophication:$\newline$ - Eutrophication refers to the process of nutrient enrichment in water bodies, leading to excessive growth of algae and depletion of oxygen.$\newline$ - This matches with iii.$\newline \bullet$b. Sanitary landfill:$\newline$ - A sanitary landfill is a method of waste disposal where waste is buried in the ground and covered with soil.$\newline$