A marketing manager set up conversion tracking and wants to add a column for conversion value per cost. How is that calculated?

It’s calculated by dividing the number in the conversions column by the total eligible interactions.
It’s calculated by dividing the total cost by the number in the conversions column.
It’s calculated by dividing the total conversion value by the total cost of all ad interactions.
It’s calculated by dividing the total conversion value by the number in the conversions column.