What optimization recommendation might you make to a new client with Shopping campaigns that don’t include all of the products the company sells?

Create a separate campaign with a high priority, and create 1 product group for all products and assign it a high bid
Create a separate campaign for all products and subdivide the inventory based on products that are already being advertised, then assign these products a low bid
Create a separate campaign for all products and subdivide the inventory using custom label attributes, then bid by item ID for the items not included in other campaigns
Create a separate campaign with a low priority, and create 1 product group for all products and assign it a low bid