Lee gave an informative speech on the poor quality of local drinking water. He brought in a test kit and presented statistics that proved local water was dangerous to drink

He advised the class to purchase a certain type of water filter pitcher guaranteed to remove these impurities. At the end of his speech, he mentioned that he worked for the company that made the pitcher and had them for sale. What was Lee's mistake?
a. Lee used too much evidence and reasoning for an informative speech.
b. Lee's speech was actually illegal, in that he was advertising in class.
c. Lee used coercion when suggesting that the audience buy the product from him.
d. Lee violated the ethical guideline of having a responsible goal for a speech.

d