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

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

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

The correct answer is:

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