Final answer:
Brita's advertisements use profit as the advertising appeal, focusing on economic benefits such as cost savings and product longevity.
Step-by-step explanation:
In Brita's advertisements for LEDs over CFLs, the advertising appeal used is b. Profit. The ads focus on the economic benefits of choosing LEDs, such as lower costs, decreased energy consumption, less frequent replacements, and extended longevity of the product. These points are emphasized to appeal to the consumer's desire to save money and gain value from their purchase, which aligns with the profit appeal in advertising strategy.