To solve this problem, we need to analyze each statement about polymers:$\newline$• Option 1: Elastomers have polymer chains held together by weak intermolecular forces.$\newline$ - This statement is correct. Elastomers are polymers with elastic properties, and their chains are held together by weak forces, allowing them to stretch and return to their original shape.$\newline$• Option 2: Fibers possess high tensile strength.$\newline$ - This statement is correct. Fibers are polymers that are strong and have high tensile strength, making them suitable for use in textiles.$\newline$• Option 3: Thermoplastic polymers are capable of repeatedly softening and hardening on heating and cooling, respectively.$\newline$ - This statement is correct. Thermoplastics can be melted and reshaped multiple times without undergoing any chemical change.$\newline$• Option 4: Thermosetting polymers are reusable.$\newline$ - This statement is incorrect. Thermosetting polymers, once set, cannot be remelted or reshaped. They form a permanent solid structure upon curing.$\newline$Therefore, the statement that is not correct is Option 4.