How could you increase the number of conversions your Shopping campaign receives for about the same total cost?

Remove product group subdivisions and bid on broader groups of products
Decrease bids for product groups with a low cost per conversion, and increase bids for product groups with a high cost per conversion
Increase bids for product groups with a low cost per conversion, and decrease bids for product groups with a high cost per conversion
Increase your campaign priority

The correct answer is:

Increase bids for product groups with a low cost per conversion, and decrease bids for product groups with a high cost per conversion.