Final answer:
The most proactive way to prove the effectiveness of an advertising campaign for a product is to ask customers how they rate the advertising and if it influenced their decision.
Step-by-step explanation:
The most proactive way to prove the effectiveness of an advertising campaign for a product is to
c. ask customers how they rate the advertising and if it influenced their decision. By directly asking customers for their feedback, you can gather valuable information about the impact of the advertising on their purchasing decisions. This approach provides concrete evidence of the campaign's effectiveness by measuring its influence on actual customers.