Why is it, when shoppers go to the grocery store, the store offers customers either plastic or paper bags to carry their groceries home?

because they are plastic shopping bags are increasingly recyclable or biodegradable .Traditional plastic bags are usually made from polyethylene, which consists of long chains of ethylene monomers. Ethylene is derived from natural gas and petroleum. The polyethylene used in most plastic shopping bags is either low-density (resin identification code or, more often, high-density (resin identification code.Color concentrates and other additives are often used to add tint to the plastic. Plastic shopping bags are commonly manufactured by blown film extrusion.

Explanation:

weathering is the answer.