To solve this problem, we need to determine the best use of Polyblend, a fine powder of recycled modified plastic. Let's analyze each option:$\newline \bullet$Option 1: Making plastic sacks$\newline$ - While Polyblend is a type of plastic, it is not specifically noted for making plastic sacks.$\newline \bullet$Option 2: Use as a fertilizer$\newline$ - Polyblend is not used as a fertilizer, as it is a plastic material and not suitable for plant growth.$\newline \bullet$Option 3: Construction of roads$\newline$ - Polyblend has been successfully used in the construction of roads. It is mixed with bitumen to enhance road durability and reduce plastic waste.$\newline$ - This makes it a good material for road construction.$\newline \bullet$Option 4: Making tubes and pipes$\newline$ - Although Polyblend is a plastic, it is not specifically used for making tubes and pipes.$\newline$Based on the analysis, the correct option is Option 3: Construction of roads.