Answer:
a message with several high-quality arguments
Explanation:
            It is a situation where I am trying to promote a new type low-fat snack food to a group of people in the grocery store.
            I learned from their behavior that they are paying attention and are trying to process my message.
           Thus I will provide useful information about the low-fat snack food. I will also try to make them understand the health benefits that these low fat food offers. I will also aware these people about the ill effects of high fat food to our health. In short I will convey strong messages with several high-quality arguments to the people in the store.
Thus the answer is "a message with several high-quality arguments."
