Which compound has a high molecular weight and is known for its durability, resembling plastic?

The correct choice is a polymer. Polymers are large, often chain-like molecules made up of repeating units called monomers. This structure gives them a high molecular weight, which is a key characteristic. Polymers are known for their diverse properties; they can be designed to be flexible, durable, and resistant to chemical degradation and environmental factors, resembling various types of plastics in their applications. This versatility allows polymers to be used in countless applications across different fields, including packaging, textiles, and engineering materials.

In contrast, while resin is a type of polymer, it typically refers to a specific subset of polymers used in adhesives, paints, and coatings, which may not necessarily have the same range of properties as other polymers. Elastomers are also polymers, but they are characterized specifically by their elastic properties, making them stretchable and rubber-like, rather than broadly high in durability and resembling plastics. Vinyl is a type of polymer (specifically polyvinyl chloride, or PVC) but it's more specific and is associated with a particular set of properties and uses, rather than representing the general concept of a high molecular weight and durable compound.