Answer:
If the intended audience doesn't really care about veganism one way or another, Marlen is right.
Step-by-step explanation:
Marlen is right because their is probability or tendency that the intended audience in which they are trying to publicized the important of Vegans to may not even care about it and as well as its important or what benefit will be derived from it this may be due to the fact that the audience are already use to abstaining from the use of the animal products, particularly in their diet either for ethical,health or due to environmental reasons which is best known to them.
The intended audience may wish not to know how important vagen is to them and their environment because some people tend to view vegans as extremists which may be one of the reason they dont care or even showed interest it.
Therefore according to Marlen having a prominent vegan (e.g., skier Heather Mills) advocate veganism will be more effective and may change people views about it